Os-E407

OFFSHORE STANDARD

The electronic p

DNV-OS-E407

Underwater Deployment and Recovery Systems

OCTOBER 2012

DET NORSKE VERITAS AS

df version of this document found through http://www.dnv.com is the officially binding version

FOREWORD

DNV is a global provider of knowledge for managing risk. Today, safe and responsible business conduct is both a licenseto operate and a competitive advantage. Our core competence is to identify, assess, and advise on risk management. Fromour leading position in certification, classification, verification, and training, we develop and apply standards and bestpractices. This helps our customers safely and responsibly improve their business performance. DNV is an independentorganisation with dedicated risk professionals in more than 100 countries, with the purpose of safeguarding life, propertyand the environment.

DNV service documents consist of among others the following types of documents:— Service Specifications. Procedural requirements.— Standards. Technical requirements.— Recommended Practices. Guidance.

The Standards and Recommended Practices are offered within the following areas:A) Qualification, Quality and Safety MethodologyB) Materials TechnologyC) StructuresD) SystemsE) Special FacilitiesF) Pipelines and RisersG) Asset OperationH) Marine OperationsJ) Cleaner EnergyO) Subsea SystemsU) Unconventional Oil & Gas

© Det Norske Veritas AS October 2012

Any comments may be sent by e-mail to [email protected]

This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of this document, and is believed to reflect the best ofcontemporary technology. The use of this document by others than DNV is at the user's sole risk. DNV does not accept any liability or responsibility for loss or damages resulting fromany use of this document.

Offshore Standard DNV-OS-E407, October 2012Changes – Page 3

CHANGES

GeneralThis is a new document.


Offshore Standard DNV-OS-E407, October 2012 Contents – Page 4

CONTENTS

CH. 1 INTRODUCTION.............................................................................................................................. 7

Sec. 1 General ................................................................................................................................................ 8

A. About this Standard...................................................................................................................................................... 8A 100 General.................................................................................................................................................................. 8A 200 Application............................................................................................................................................................ 8A 300 Objective ............................................................................................................................................................... 8A 400 Scope..................................................................................................................................................................... 8A 500 Deviations ............................................................................................................................................................. 9

B. Application of the Technology ..................................................................................................................................... 9B 100 General.................................................................................................................................................................. 9

C. Types of Underwater Deployment and Recovery Systems........................................................................................ 9C 100 General.................................................................................................................................................................. 9

D. Qualification of New Technology............................................................................................................................... 10D 100 General................................................................................................................................................................ 10D 200 Composition analysis .......................................................................................................................................... 11D 300 Interface analyses................................................................................................................................................ 12D 400 Contributions ...................................................................................................................................................... 12D 500 External action analysis ...................................................................................................................................... 13D 600 System interaction analysis................................................................................................................................. 13D 700 Selection of qualification strategy ...................................................................................................................... 14

E. Assuring Safety and Reliability ................................................................................................................................. 14E 100 General................................................................................................................................................................ 14

F. References .................................................................................................................................................................... 15F 100 General................................................................................................................................................................ 15F 200 Normative references .......................................................................................................................................... 16F 300 Informative references ........................................................................................................................................ 16F 400 Other informative references .............................................................................................................................. 16

G. Definitions .................................................................................................................................................................... 17G 100 Verbal forms ....................................................................................................................................................... 17G 200 Terms .................................................................................................................................................................. 17

CH. 2 REQUIREMENTS ........................................................................................................................... 20

Sec. 1 General ............................................................................................................................................. 21

A. Introduction................................................................................................................................................................. 21A 100 Objective ............................................................................................................................................................. 21

B. Qualification Documentation ..................................................................................................................................... 21B 100 Qualification evidence and argument ................................................................................................................. 21

C. Roles and Responsibilities .......................................................................................................................................... 21C 100 User, system integrator, independent verifier and sub-system suppliers............................................................ 21

D. Qualification Strategy................................................................................................................................................. 22D 100 Main unknown elements ..................................................................................................................................... 22D 200 Documentation.................................................................................................................................................... 22

Sec. 2 Service Context ................................................................................................................................ 24

A. Documentation Requirements ................................................................................................................................... 24A 100 General................................................................................................................................................................ 24

Sec. 3 The Integrated System ..................................................................................................................... 25

A. Documentation Requirements .................................................................................................................................. 25A 100 Introduction......................................................................................................................................................... 25A 200 Functional description......................................................................................................................................... 25A 300 Failure modes...................................................................................................................................................... 25

Sec. 4 Sub-systems....................................................................................................................................... 26

A. Introduction................................................................................................................................................................. 26A 100 Documentation requirements .............................................................................................................................. 26



B. Rope Units.................................................................................................................................................................... 26B 100 Fibre rope unit..................................................................................................................................................... 26B 200 Wire rope unit ..................................................................................................................................................... 26B 300 Hang-off fibre rope assemblies........................................................................................................................... 26B 400 Condition management ....................................................................................................................................... 26B 500 Rope performance in the service context............................................................................................................ 27B 600 Technology qualification and rope performance ................................................................................................ 27B 700 Generic failure modes for the fibre rope unit...................................................................................................... 27

C. Mechanical Lifting Appliance.................................................................................................................................... 27C 100 General................................................................................................................................................................ 27

D. Power and Control Systems ....................................................................................................................................... 28D 100 Power systems..................................................................................................................................................... 28D 200 Control systems................................................................................................................................................... 28

E. Software Systems......................................................................................................................................................... 28E 100 General................................................................................................................................................................ 28E 200 Software dependent systems............................................................................................................................... 28

CH. 3 CLASSIFICATION AND CERTIFICATION .............................................................................. 29

Sec. 1 Classification..................................................................................................................................... 30

A. General ......................................................................................................................................................................... 30A 100 General................................................................................................................................................................ 30

Sec. 2 Certification ...................................................................................................................................... 31

A. Introduction................................................................................................................................................................. 31A 100 General................................................................................................................................................................ 31A 200 Main elements in certification ............................................................................................................................ 31A 300 Approval of manufacturer................................................................................................................................... 31A 400 Overview of the certification process ................................................................................................................. 31A 500 Timelines ............................................................................................................................................................ 32A 600 Inspection release notes ...................................................................................................................................... 32A 700 Confidentiality .................................................................................................................................................... 32

B. Service Context............................................................................................................................................................ 32B 100 Introduction......................................................................................................................................................... 32B 200 Operation of “Underwater deployment & recovery systems” ............................................................................ 32B 300 Condition management programme.................................................................................................................... 32B 400 Marine operations requirements ......................................................................................................................... 32

C. Certification of the Integrated System ...................................................................................................................... 32C 100 Roles, responsibilities ......................................................................................................................................... 32C 200 Request for certification...................................................................................................................................... 32

D. Sub-system Certification ............................................................................................................................................ 33D 100 General................................................................................................................................................................ 33D 200 Fibre rope unit..................................................................................................................................................... 33D 300 Wire rope unit ..................................................................................................................................................... 33D 400 Fibre rope assemblies.......................................................................................................................................... 33D 500 Mechanical lifting appliance............................................................................................................................... 33D 600 Power systems..................................................................................................................................................... 34D 700 Control systems................................................................................................................................................... 34D 800 Software systems ................................................................................................................................................ 34

E. Recertification ............................................................................................................................................................. 34E 100 General................................................................................................................................................................ 34

Sec. 3 Technology Qualification................................................................................................................. 35

A. General ......................................................................................................................................................................... 35A 100 Technology qualification assistance ................................................................................................................... 35

Sec. 4 Marine Operations ........................................................................................................................... 36

A. Marine Operations ...................................................................................................................................................... 36A 100 Verification of “Marine operations” requirements ............................................................................................. 36A 200 Marine warranty survey ...................................................................................................................................... 36

App. A Certificate Example.......................................................................................................................... 37

App. B Argumentation in Qualification Strategy ...................................................................................... 38



A. Establishing an Assurance Case ................................................................................................................................ 38A 100 General................................................................................................................................................................ 38

B. Qualification Strategy ................................................................................................................................................ 38B 100 General ............................................................................................................................................................... 38

C. Simplification by Qualification Strategy................................................................................................................... 39C 100 General................................................................................................................................................................ 39

D. Characterisation of System Variants for DDRS ...................................................................................................... 39D 100 General................................................................................................................................................................ 39

E. Test Design................................................................................................................................................................... 40E 100 General................................................................................................................................................................ 40

App. C Qualifying the Fibre Rope Unit for Deepwater Deployment & Recovery Systems ................... 41

A. Qualifying the Fibre Rope Unit ................................................................................................................................. 41A 100 Introduction......................................................................................................................................................... 41A 200 Approaches ......................................................................................................................................................... 41

B. The Performance of Fibre Rope Units ...................................................................................................................... 42B 100 General................................................................................................................................................................ 42

C. Critical Parameters..................................................................................................................................................... 42C 100 Introduction......................................................................................................................................................... 42

D. Failure Modes .............................................................................................................................................................. 43D 100 Introduction......................................................................................................................................................... 43D 200 Overloading ........................................................................................................................................................ 43D 300 Time dependent failure ....................................................................................................................................... 43D 400 Processes pertaining to bending.......................................................................................................................... 43D 500 Twisting .............................................................................................................................................................. 43D 600 External wear ...................................................................................................................................................... 43

E. Interaction between Failure Modes........................................................................................................................... 44E 100 General................................................................................................................................................................ 44

App. D Graphical Presentations .................................................................................................................. 45

A. Presenting Arguments Graphically ........................................................................................................................... 45A 100 Introduction......................................................................................................................................................... 45

B. Goal Structuring Notation (GSN).............................................................................................................................. 45B 100 General................................................................................................................................................................ 45

C. Kaos .............................................................................................................................................................................. 47C 100 General................................................................................................................................................................ 47


OFFSHORE STANDARDDNV-OS-E407

UNDERWATER DEPLOYMENT &RECOVERY SYSTEMS

CHAPTER 1

INTRODUCTION

CONTENTS PAGE

Sec. 1 General ............................................................................................................................ 8


Offshore Standard DNV-OS-E407, October 2012Ch.1 Sec.1 – Page 8

SECTION 1GENERAL

A. About this Standard

A 100 General

101 This standard covers requirements to Underwater Deployment & Recovery Systems.

102 Chapter 1 (this chapter) provides a general introduction with overview, definitions, general provisionsand references relevant for Chapter 2 and Chapter 3. Chapter 2 provides the requirements of this standard andthe associated responsibilities. Chapter 3 covers the process of certification of compliance with this standard.

Guidance note:This standard is based on requirements derived from phase 1 of the Joint Industry Project ‘Certification of DeepwaterInstallation Systems’. On basis of phase 2, an update of this standard will be published in October 2013, with apreceding draft available to the JIP participants prior to publication. Notwithstanding the planned update, the currentissue of this standard is complete, accurate and fulfilling for its purpose.

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103 The current, official issue of this standard and other DNV service documents is available at http://www.dnv.com/resources/rules_standards/index.asp.

A 200 Application

201 This standard is applicable to hoisting systems that utilise rope in order to place or remove objectsunderwater.

A 300 Objective

301 The objective of this standard is to provide requirements for system integration and documentation of thesafety and reliability for Underwater Deployment & Recovery Systems, and to provide a framework forverification and certification.

Guidance note:Why:

The need for an all-encompassing standard for Underwater Deployment & Recovery Systems arises from thecomplexity of the systems. It will not be possible to verify the integrated system by just verifying its parts. This isbecause these parts interact when the system performs its functions, and therefore the way the interaction takes placeis critical to safety and reliability.In this way, these systems are comparable to an automobile, a system which also is designed, built and verified as awhole; it includes operating interfaces, mechanical parts, rotating machinery and controls, sensors and software. Thesafety and reliability is provided by the integrated system and its service context as given by driver training andexperience, traffic law, road conditions, maintenance programme, etc.

How:The method for technology qualification defines a structured work process to prove that Underwater Operations canbe performed safely and reliably with an Underwater Deployment & Recovery System on certain conditions. Thoseconditions usually define the loading, operation time, maintenance, wave height and other factors relating to the useof the system, and are referred to as the service context in this standard.The functions of the Underwater Deployment & Recovery System shall be proven safe and reliable, so systeminteraction and external action are analysed to find out what test results and associated argument will be required.The description of the safety and reliability of Underwater Operations as defined by technology qualification andvalidated existing requirements or procedures shall be provided as an assurance case.


A 400 Scope

401 This standard specifies requirements for technology assurance pertaining to safety and reliability ofUnderwater Deployment & Recovery Systems including system integration, design, materials, and methods ofmanufacture and testing.

402 It applies to the integrated Underwater Deployment & Recovery System with its individual sub systemsand interfaces; all of which shall be verified with respect to the service context defined by the designated use.

403 This standard can be used as a reference for contracts between parties.

404 This standard does not cover the components and systems in the suspended mass, including the subseatool. However, suspended mass and added mass will influence system response and will have to be consideredin order to derive the load cases.


http://www.dnv.com/resources/rules_standards/index.asp


Guidance note:The subsea tool and connection elements should be managed with the same goal of assuring safety and reliability asinferred from this standard.


405 The process for provision of evidence that a technology will function within specified limits with anacceptable level of confidence is called Technology Qualification. This standard assumes that therecommendations provided in DNV-RP-A203 ‘Qualification of New Technology’ are followed.406 This standard requires an assurance case approach for presentation of the documentation for theintegrated Underwater Deployment & Recovery System.

Guidance note:Based on DNV-RP-A203, ‘qualification documentation’ for new technology comprises the ‘qualification evidence’obtained from tests or analyses, and the ‘argument’ applied to warrant the claim that the technology is safe andreliable.


A 500 Deviations501 Since this standard is governed by the principles for qualification of new technology, substantiateddeviations from provisions of this standard or a normative reference can be acceptable.

Guidance note:Compliance with informative references or other references is not mandatory under this standard.


B. Application of the Technology

B 100 General101 The Underwater Deployment & Recovery System is operated in order to place or remove objects underwater, including on the sea bed in several thousand metres of water. The system will perform as an integral partof Underwater Operations in which usage of the system and condition of the system are important elements tooverall safety and reliability.

C. Types of Underwater Deployment and Recovery Systems

C 100 General101 Underwater deployment & recovery systems can be of three different types:

102 ‘Deepwater’ systems are characterised by the use of continuous fibre rope from the mechanical liftingappliance to the sea bed, whereas ‘Subsea’ systems use a continual length of steel-wire rope. The ‘Hang-off’systems use fibre ropes or tethers to extend the reach of an existing hoisting system such as an offshore crane.Reference is made to Ch.1 Figure 1.

— Deepwater Deployment & Recovery Systems (DDRS)— Subsea Deployment & Recovery Systems (SDRS)— Hang-off Deployment & Recovery Systems (HDRS)



Figure 1 Illustration of the three types of underwater deployment & recovery systems.

Guidance note:At this stage this standard is developed primarily for “Deepwater deployment & recovery systems” with the elementsof new technology pertaining to fibre ropes in mind.“Subsea deployment & recovery systems” and “Hang-off deployment & recovery systems” shall be subjected to thesame requirements for assurance documentation as the “Deepwater deployment & recovery systems” for compliancewith this standard.This standard uses the term “Underwater deployment & recovery systems” in statements that are general to all threetypes of system, and the term “Deepwater deployment & recovery system” in statements pertaining to the use of fibrerope on the mechanical lifting appliance. More specific distinction can be made in subsequent revisions of thisstandard.


D. Qualification of New Technology

D 100 General101 In order to arrive at a sufficient level of documentation for a technology which contains unprovenelements, it will be necessary to go through a “Technology Qualification” process. This can be due to thenovelty of the technology itself, or the novelty of the service context.102 The objective of the “Technology Qualification” is to provide the necessary evidence so that safety andreliability of the system will be proven, and the main steps of the basic process are illustrated in Ch.1 Figure 2.

Crane wire (HDRS)Fibre tether (HDRS)

Suspended mass

Fibre rope (DDRS) / Steel wire rope (SDRS)



Figure 2 The basic process for qualification of new technology according to DNV-RP-A203.

103 “Technology Qualification” activities can be performed in any phase of the development of a newtechnology, not excluding formalised “Technology Qualification” after the development has been concluded.In order to optimise the processes of development and qualification it is recommendable to perform“Technology Qualification” integrated with the technology development.

Guidance note:Design and engineering processes contain large elements of technology qualification by their nature, which can beused in the formalised technology qualification process for establishment of qualification documentation. In fact,Technology Qualification is merely a certain systematic way of providing argument and evidence to substantiate theclaim that the technology is safe and reliable within defined limits. One of the greatest advantages of formalisedTechnology Qualification is avoidance of tests that drain a limited budget or spend too valuable time.


D 200 Composition analysis201 The technology composition analysis is a key part of the methods for qualification of new technology.A high-level composition analysis for underwater operations is shown in Ch.1 Figure 3.

Qualification BasisSet the requirements

Technology AssessmentNovelty and prohibitive obstacles

Qualification planSelect qualification methods

Threat AssessmentFailure modes and risks

Execution of the planCollect evidence

Performance assessmentVerify compliance with requirements

Mod

ifica

tions

Requirementsmet?

Qualification state attained

Yes

No



Figure 3 Sub-system decomposition for underwater operations.

202 As illustrated in Ch.1 Figure 3, several technical systems have to operate together in order to performsafe and reliable “Underwater Operations”; and simultaneously systematics have to be applied in interactionwith the technical systems, being operating procedures (for the “Underwater deployment & recovery system”),marine operations involving vessels and objects, and condition management (of the “Underwater deployment& recovery system”).203 Following the top-level decomposition shown in Ch.1 Figure 3, the interfaces for the UnderwaterDeployment & Recovery System should be analysed further.

D 300 Interface analyses301 Interface analyses can be effective with respect to identification of failure modes compared to the sub-system decomposition alone, as shown in Ch.1 Figure 3.302 There are two types of interfaces, as identified by

— External action on the integrated system.— System interaction between sub systems.

D 400 Contributions401 On each of the interfaces, the system functions will be provided by the contributions from the elementson each side of the interface.402 For development of the required documentation to qualify a system, the contributions to functions acrossinterfaces should be defined in the qualification basis.

Guidance note:See DNV-RP-A203 for the recommendations pertaining to the qualification basis.


UnderwaterOperations

ServiceContext

Underwater Deployment &

Recovery System

Mechanical Lifting

Appliance

Power, Sensors,Control & Software

RopeUnit

BoundaryConditions

ConditionManagement

SuspendedMass InspectionInspection

MaintenanceMaintenance

MonitoringMonitoringSystemOperationMarineOperations



D 500 External action analysis

Figure 4 External action interfaces (arrows).

D 600 System interaction analysis

601 In the same way as the external action analysis, system interfaces should be analysed with respect tofailure modes and how they should be managed. Ch.1 Figure 5 indicates some system interfaces for the ropeunit.

Figure 5 System interfaces for the Rope Unit (arrows).



D 700 Selection of qualification strategy

701 The best qualification strategy will depend on the existing qualification state and on available time,budget and other factors. As discussed in DNV-RP-A203, an incremental qualification strategy can beadvantageous, in particular for integrated technologies.

702 The principle of a qualification strategy in relation to the basic “Technology Qualification” process isshown in Ch.1 Figure 6.

Guidance note:In order to choose a suitable qualification strategy for a complex system, the following should be addressed:

— What would be the minimum qualification documentation required before entering into a narrow service context?— How can the experience from this service be used as qualification evidence?— How will the argument for safety and reliability need to be modified and updated?— Is the system controlling redundant or controlling dependent?


Figure 6 Strategy with “Technology Qualification” stages instead of just the single, basic process.

Guidance note:Methods for management of the qualification phases from narrow to full service context can be reflected in laterversions of this standard and in the preceding drafts.


703 Additional information on qualification strategy can be found in Appendix B.

E. Assuring Safety and Reliability

E 100 General

101 This standard defines system-level requirements to documentation for all types of “Underwaterdeployment & recovery systems”. It shall be substantiated how the integrated system is safe and reliable withinthe designated service context.



102 Hence, the functions of the integrated system shall be proven sufficiently safe and reliable. “UnderwaterOperations” will involve external action when system functions are delivered as indicated in Ch.1 Figure 4.This delivery of system functions relies on the subsystems delivering their functions through system interactionas indicated in Ch.1 Figure 5 for the rope unit.

103 The system safety and reliability claim shall be substantiated with an expressed argument thatunambiguously connects qualification evidence and other evidence to the claim. Reference is made toAppendix B.

104 The principle for combination of requirements from existing standards with “Qualification of NewTechnology” is illustrated in Ch.1 Figure 7.

Figure 7 Technology assurance combines ‘Technology Qualification’ for new elements, and ‘RequirementsValidation’ for known elements in order to claim that the technology is safe and reliable.

105 The ‘Requirements Validation’ is performed in order to warrant disregard of irrelevant requirements inexisting standards, procedures or practices.

Guidance note:

Should a sub system supplier require a deviation or waiver from a normative reference for the specific case, thenRequirements Validation can be used to substantiate the request. This standard requires assurance documentation(evidence and argument) in order to substantiate the claim for safety and reliability.

Some form of graphical presentation of the technology qualification documentation is recommended for the sake ofoverview and traceability; however this is not mandatory under this standard. The assurance case can be provided ina graphical structure that describes the relationship between the qualification evidence and the claim through theargument. Goal Structure Notation (GSN) /1/ or KAOS /2/ can be used for this purpose. See also Appendix D.


F. References

F 100 General

101 In case of conflict between requirements of this standard and a reference document, the requirements ofthis standard should prevail.

102 The latest edition of referenced documents (including amendments and corrections) should apply.

Claim:The Technology is Safe and Reliable

Qualification ofNew Technology

Existing Requirements

Warrant:Safety and reliability can be

substantiated by Technology Assurrance

FailureModes

SystemFunctions

ProvideEvidence

RequirementsValidation

Existing Standardsor Practices

ProvideEvidence



F 200 Normative references

201 The DNV documents listed in Table D1 include provisions, which through reference in the text constituterequirement of this standard.

F 300 Informative references

301 In addition to non-referenced parts of the documents in Table D1, the DNV service documents listed inTable D2 contain information that may be of value to the reader of this standard.

Guidance note:

The DNV service documents are available at http://www.dnv.com/resources/rules_standards/index.asp. Servicedocuments not yet in effect pr. October 2012 are indicated by italic letters in Tables D1 and D2.


F 400 Other informative references

401 The following references provide guidance on graphical presentation of arguments that may be of valueto the reader of this standard. See also Appendix D.

Table D1DNV-OS-D202 Automation, Safety, and Telecommunication SystemsDNV-OS-D203 Integrated Software Dependent System (ISDS)DNV-OS-E303 Offshore Mooring Fibre Ropes, October 2010.

Offshore Fibre Ropes, planned re-issue December 2012DNV-RP-A203 Qualification of New TechnologyDNV Standard for Certification 2.22 Lifting AppliancesDNV Standard for Certification 2.9,Approval Programme No. 321

Offshore Mooring Fibre Ropes, November 2010.Manufacturers of Offshore Fibre Ropes, planned re-issue December 2012

DNV Standard for Certification 2.9,Approval Programme No. 322

Yarns for Offshore Mooring Fibre Ropes, November 2010.Manufacturers of Offshore Fibre Yarns, planned re-issue December 2012

Table D2DNV Rules for Classification of Ships, Pt. 1 Ch. 2

Class Notations

DNV Rules for Classification of Ships, Pt. 4 Ch. 9

Control and monitoring systems

DNV Rules for Classification of Ships, Pt. 5 Ch. 7

Offshore Service Vessels, Tugs and Special Ships

DNV-OSS-401 Technology Qualification ManagementDNV-OS-D101 Marine and Machinery Systems and EquipmentDNV-OS-D201 Electrical InstallationsDNV-OS-E402 Diving SystemsDNV-OS-H101 Marine Operations, GeneralDNV-OS-H102 Marine Operations, Design and FabricationDNV-OS-H204 Marine Operations, Offshore Installation (under development)DNV-OS-H205 Marine Operations, Lifting (under development)DNV-OS-H206 Marine Operations, Subsea (under development)DNV-RP-A201 Plan Approval Documentation Types – DefinitionsDNV-RP-D201 Integrated Software Dependent SystemsDNV-RP-E304 Damage Assessment of Fibre Ropes for Offshore Mooring, April 2005.

Condition Management of Offshore Fibre Ropes, planned re-issue 2013DNV-RP-E305 Design, Testing and Analysis of Offshore Fibre Ropes, planned December 2012DNV-RP-H101 Risk Management in Marine and Subsea OperationsDNV-RP-H102 Marine Operations during Removal of Offshore InstallationsDNV-RP-H103 Modelling and Analysis of Marine Operations

Table D3/1/ Origin Consulting (York) Ltd.,

on behalf of the ContributorsGSN Community Standard Version 1, November 2011 http://www.goalstructuringnotation.info/documents/GSN_Standard.pdf

/2/ Respect-IT A KAOS Tutorial V1.0, Oct. 2007 http://www.objectiver.com/fileadmin/download/documents/KaosTutorial.pdf


http://www.objectiver.com/fileadmin/download/documents/KaosTutorial.pdf


http://www.goalstructuringnotation.info/documents/GSN_Standard.pdf


G. Definitions

G 100 Verbal forms101 Shall: Indicates a mandatory requirement to be followed for fulfilment or compliance with the presentstandard. Deviations are not permitted unless formally and rigorously justified, and accepted by all parties.102 Should: Indicates a recommendation that a certain course of action is preferred or particularly suitable.Alternative courses of action are allowable under the standard when agreed between contracting parties, butshall be justified, documented and approved by DNV.103 May: Indicates permission, or an opinion, which is permitted as a part of conformance with the standard.104 Can: Indicates a conditional possibility.

G 200 Terms201 The set of terms defined in DNV-RP-A203 ‘Qualification of New Technology’ applies under thisstandard together with the following set of terms.

Assurance argument: The substantiated relationship between a documented body of evidence and the claim that the technology is safe and reliable when used within the service context.

Assurance case: A body of evidence organized into an argument demonstrating that some claim about a system holds, i.e. is assured.

Contribution: ‘Contribution’ is what is provided from an element on one side of an interface, in order that the system delivers its functions applicable to that interface.

Deepwater Deployment & Recovery System (DDRS):

Hoisting system that operates fibre rope in order to place or remove objects underwater.

Defined break tension: The break strength of the rope as verified by testing according to a defined procedure, which includes the rate of application of tension.

External interface: The interfaces at which a system is subjected to external influence, such as operation of an integrated system, or where it is connected to the vessel or the suspended mass. For a sub system such as the fibre rope unit, the interaction with the MLA takes place on an external interface, which in turn is a system interface for the integrated system.

Design Verification Report (DVR):

The DVR is a report issued by the independent verifier on basis of review of design documentation (e.g. in the certification process).

Functional description: Technology Composition Analysis pertaining to functions and sub functions of the integrated system.

Functional Specification: The requirements of the user to how the system shall perform.Hang-off Deployment & Recovery System (HDRS):

Hoisting system that uses fibre rope to extend its reach.

Independent verifier: The entity that verifies the qualification documentation and satisfaction of the claim of safety and reliability on behalf of the System Integrator.

Margin: A measure of the safeguard against loss of function for a given failure mode. Usually expressed as the ratio between the failure state and the present state of the critical parameter, but can also be a fixed value. There will be one margin for each of the relevant failure modes.

Maximum system tension: The highest permissible, momentary tension measured in real-time at the vessel.

Maximum working depth: The maximum permissible water depth.Mechanical LiftingAppliance (MLA):

The Lifting Appliance sub system, not including power, controls, sensors and software systems or the rope unit.

Narrow service context: The service context for a system which is not in its final qualification state will have more restrictions in order to substantiate the claim, i.e. be narrower than the service context for the final qualification state.

PDF (file type): Portable Document Format.Phase difference: The time difference between two waves having the same frequency, for

example between force action and resulting displacement.Qualification documentation: The qualification documentation consists of the qualification evidence and the

associated argument intended to claim that the technology is qualified.



Qualification evidence: Results from testing or analyses acquired based on the principles described in DNV-RP-A203 that can be used to prove that a technology is safe and reliable within its service context.

Qualification of technology: Qualification is the process of providing the evidence and the argument that the technology will function within specified limits with an acceptable level of confidence.

Qualification stage: 1) The basic technology qualification process as performed to improve the specified limits within which the technology is qualified.

2) Technology qualification for stricter limits than the final goal.Qualification state: The degree to which the technology is qualified, as defined by the

qualification basis of the completed qualification stage.Requirements validation: Assessing existing requirements or recommendations for relevance using

“Technology Qualification” principles. (See Guidance Note below.)Reliability: The ability of operations, systems or components to perform intended

functions under stated conditions for a specified period of time.Reverse bend cycle: Two single bend cycles in opposite direction.Rope: The assembly of strands that constitute the (long length of) rope without

termination.Rope Performance Description (RPD):

A document which describes the relationship between tension (on the rope), bending or twisting (of the rope) and local stresses (in the rope).

Rope twist: Torsional deflection of the Fibre Rope. Two points that restrict the rope counter rotate around the rope axis.

Rope unit: Long length of rope including end termination.Safety: The ability of operations, systems or components to avoid harm to people or

to the environment.Safety factor: Use of the term ‘safety factor’ is discouraged since it is not an adequate

measure of safety in Underwater Deployment & Recovery Systems. The term has traditionally been used to refer to the ratio between the rope minimum break strength and the occurring tension.

Service context: The boundary conditions for the validity of the Technology Qualification as defined by system operating procedures, marine operations requirements and the condition management program.

Service context specification: The specification from the user to the system integrator for the operation, condition management and marine operations pertaining to the Underwater Deployment & Recovery System.

Single bend cycle: The fibre rope is bent and straightened on a sheave or drum.Subsea Deployment & Recovery System (SDRS):

Hoisting system that operates steel-wire rope in order to place or remove objects underwater.

Sub-system supplier: The company that is responsible for the delivery of a sub system such as for example the Mechanical Lifting Appliance to the System Integrator.

Suspended mass: The mass of elements attached to the fibre rope unit; includes the payload and loose gear such as slings, lifting beams, frames, tools, connectors, etc.

System integrator: The party that is responsible for the acquisition of sub systems and how the system delivers its functions when assembled, in the defined service context. The system integrator provides the integrated Underwater Deployment & Recovery System to the user.

System interface: Interface between sub systems within an integrated system, for example between the rope path and the rope, or between the power sub system and the MLA.

Technology assurance: The combined approach of using technology qualification with validation of existing requirements or practices to assure safety and reliability of a technology for a designated service context.

Tension ratio: The ratio between actual tension and the defined break tension for the rope.Termination: The mechanical transition between the fibre rope and the suspended mass. For

other types of fibre rope termination than spliced eye an appropriate level of qualification is required, ref. DNV-OS-E303.

Test design: The process of defining required testing in the Qualification Plan in order to produce defined evidence, as needed for the argument to claim the technology proven.



Guidance note:It is usually preferable to exclude existing sets of requirements or recommendations that are marginally relevant andperform “Technology Qualification” independently, instead of being restricted by irrelevant provisions that do notadd value to the technology assurance process.


Underwater deployment & recovery system:

Hoisting system suited to place or remove objects underwater.

Underwater operations: The systems, equipment and methods employed to manipulate an object to/from a vessel and to/from the underwater position.

User: The company that acquires an “Underwater deployment & recovery system” from the “System integrator” in order to operate it in the intended context. It is assumed that the “User” will be both the “Owner” and the “Operator” of the system.

VMO Standard: All the DNV offshore standards covering marine operation, i.e. DNV-OS-H101, DNV-OS-H102 and DNV-OS-H201 through DNV-OS-H206, which replace “DNV - Rules for planning and execution of marine operations”.




CHAPTER 2

REQUIREMENTS

CONTENTS PAGE

Sec. 1 General .......................................................................................................................... 21Sec. 2 Service Context............................................................................................................. 24Sec. 3 The Integrated System .................................................................................................. 25Sec. 4 Sub-systems .................................................................................................................. 26



SECTION 1 GENERAL

A. Introduction

A 100 Objective101 This chapter describes how an integrated “Underwater deployment and recovery system” should bedocumented in order to warrant that the system is safe and reliable for its designated service context.102 A “Technology qualification” claim shall be substantiated by qualification documentation, whichconsists of a body of evidence and the associated argument that ties the evidence and the claim together.

Guidance note:The substantiated evidence – argument – claim relationship is referred to as an assurance case.


103 “Underwater deployment & recovery systems” shall be qualified with respect to their sub systems,system interaction on interfaces between sub systems, external action and their service context. Thus, therequirements for “Underwater deployment & recovery systems” will be of three types:

— Service context requirements— System requirements— Sub-system requirements.

Reference is made to Ch.1 Figure 3.Guidance note:The sub systems, components and mode of operation of “Underwater deployment & recovery systems” will not befixed, since these details will depend on their design.Hence, the extent of analyses and testing required for establishing qualification documentation will not be fixed. Theservice context as defined by system operation, condition management and marine operations will vary accordingly.


B. Qualification Documentation

B 100 Qualification evidence and argument101 The qualification documentation consists of the qualification evidence and the argument that supportsthe claim that the technology is proven in the service context.102 The system integrator should formulate an argument to demonstrate how the qualification evidencerelate to the claim. This should be done according to the basic process as outlined in DNV-RP-A203 to providea structured presentation of how the qualification evidence relates to the claim.103 In the context of the intended use (the service context), the failure modes of the integrated system shallbe identified. It shall be argued how they are managed within the scope of the condition managementprogramme for the system, the system operating procedures, and the marine operations requirements.104 All documentation shall be available electronically as secured PDF documents, traceable with respect toversion and issue date and with signatures from the issuing party.105 All documents should be indexed with bookmarks and enabled for commenting.

C. Roles and Responsibilities

C 100 User, system integrator, independent verifier and sub-system suppliers101 The “User” is responsible for the service context in which the “Underwater deployment & recoverysystem” will be operated.102 The “System integrator” is responsible for the various individual sub-systems working together toprovide the desired functions of the integrated system. The necessary documentation shall be provided for the“Independent verifier” and as required by the “User”.103 The role of the “Independent verifier” is to perform a design verification of the documentation of theintegrated system.104 Sub-system suppliers shall provide the deliveries to the “System integrator” with appropriatedocumentation and in accordance with specifications.



105 A basic hierarchy of responsibility for system integration, sub systems and products is shown in Ch.2Figure 1.

Figure 1 An example of chain of responsibilities.

Guidance note:Presently, this standard defines the “User” role, which includes the roles of “Owner” and “Operator”. If of benefit tothe industry, this standard will be modified to define the “Owner” and “Operator” roles in place of the role of “User”.


D. Qualification Strategy

D 100 Main unknown elements

101 The optimal qualification strategy will depend on which are the main unknowns for the particular systemwithin its particular service context.

Guidance note:When the qualification strategy is being established then the “User” and the “System integrator” should liaise closelyin order to define the balance between initial qualification state and the required qualification state for the full servicecontext, and to establish the best plan for progressing the qualification state based on “Technology qualification”principles according to DNV-RP-A203 applying in-service experience gathering as one of the qualification activities.


D 200 Documentation

201 With a staged qualification strategy rather than full, initial qualification prior to service, the objective ofthe qualification documentation is to demonstrate safety and reliability within the “Narrowed service context”that shall be defined for each state in the qualification strategy.202 A plan for expansion of the service context should be established for each qualification stage, after whichthe qualification documentation should be updated to reflect the achieved qualification state. Reference is madeto the illustration in Ch1. Figure 6.

User

SystemIntegrator

IndependentVerifier

Rope UnitSupplier

MLASupplier

Supplier of Power,

Controls & Sensors Systems

Loadbearing MaterialSupplier

CoatingSupplier

Termination HardwareSupplier

Winch Supplier

Rope Guide Path Supplier

Power Systems Supplier

Control SystemsSupplier

InstrumentationSupplier

SoftwareSupplier



203 The progression from one qualification state to the next can depend on the collection of evidence frominitial service, or on the results of testing that take a long time to complete.204 Definition of the optimal qualification strategy will in a large part consist of striking the right balancebetween knowledge of the rope condition during service and how accumulation of damage will be progressingin continued service. More information on qualification strategy can be found in Appendix B.



SECTION 2 SERVICE CONTEXT

A. Documentation Requirements

A 100 General101 As illustrated in Ch.1 Figure 3 the “Underwater deployment & recovery systems” will operate in aservice context which is defined by the programme for condition management, operating procedures for the“Underwater deployment & recovery system” and the marine-operation boundary conditions associated with“Underwater operations” to be performed with the system.102 It is the responsibility of the “User” to submit the “Service context specification” to the “Systemintegrator”.

Guidance note:The “System integrator” is responsible for the system delivery to the user, and for the interaction with all sub systemsuppliers and the independent verifier.


103 It is the responsibility of the “System integrator” to submit to the “User” the service context that isinferred by the “Underwater deployment and recovery system”, in the current qualification state, and fullyqualified for the intended use. The service context defines the boundary conditions for the “Technologyqualification” of the “Underwater deployment and recovery system” in the context that defines the“Underwater operations”.

Guidance note:In this current issue of this standard the “User” and the “System integrator” are required to establish the “Servicecontext specification” and “Service context” on basis of own methods.Methods to match the “Service context” with the “Service context specification” and the “Technology qualification”program can be reflected in later versions of this standard and in the preceding drafts.


104 The qualification documentation shall demonstrate that “Underwater operations” can be performedsafely and reliably within the “Service context” for the “Underwater deployment & recovery system”.

Guidance note:The service context documents (Operating Procedures, Marine Operations Requirements and Condition ManagementProgramme) should address parameters such as hoist speed, depth, vessel motions, static- & dynamic loading,monitoring possibilities, alarms, etc.


105 It is the responsibility of the “User” to ensure that provisions stated in document “Marine operationsrequirements” are adhered to.106 It is recommended to apply the VMO Standard for verification of compliance when the operatingprocedures for the “Underwater deployment & recovery system” and the “Marine operations” requirements aredeveloped.



SECTION 3THE INTEGRATED SYSTEM

A. Documentation Requirements

A 100 Introduction101 This section covers the documentation requirements for the integrated “Underwater deployment &recovery system”.102 The documentation shall demonstrate assured safety and reliability in the “Service context” defined bysystem operation, system condition management and marine-operation boundary conditions.103 It is the responsibility of the “System integrator” to provide the system documentation.

A 200 Functional description201 A functional description shall be submitted for the integrated “Underwater deployment & recoverysystem. It shall provide an overview of the system in general.202 The functional description shall explain how the system delivers its functions as an integrated whole bydelivery of functions at the interfaces.203 Technology composition analysis should be applied to functions on interfaces in order to reflect howeach function is delivered.204 The external interaction between the system and the surroundings shall be described. For each externalinterface (Ch.1 Figure 4), aspects of particular importance shall be identified; and it shall be explained howthey are managed by system qualification in order to warrant the claim for assured safety and reliability.205 The functional interaction between the various sub systems shall be described. For each system interface(Ch.1 Figure 5), aspects of particular importance shall be identified; and it shall be explained how they aremanaged by system qualification in order to warrant the claim for assured safety and reliability.

Guidance note:The current version of this standard requires the system integrator and sub-system providers to apply own methods toestablish system functions for use in the “Technology Qualification” program. Methods can be reflected in laterversions of this standard and in the preceding drafts.


A 300 Failure modes301 Failure modes shall be managed through “Technology Qualification” principles according to DNV-RP-A203.302 Failure modes that are well understood and covered by existing standards can be claimed sufficientlymanaged through adherence to standards. The appropriate claim shall be substantiated, and the relevant partsof the referenced standard shall be validated.

Guidance note:Reference is made to the ‘Requirements validation’ indicated in Ch.1 Figure 7. The relevance of certain requirementsof an existing standard should be substantiated by application of “Technology qualification” principles with basis inDNV-RP-A203.




SECTION 4SUB-SYSTEMS

A. Introduction

A 100 Documentation requirements

101 This section covers requirements for the documentation of the sub systems within “Underwaterdeployment & recovery systems”.

102 Each of the sub systems that make up the “Underwater deployment & recovery system” shall bedocumented according to relevant parts of standards listed in Table D1.

103 Where standards are lacking or insufficient, then technology qualification shall be performed. A ‘Requirements validation’ is indicated to the right in Ch.1 Figure 7 to show that standards need to be checkedfor applicability.

Guidance note:Should a sub system supplier require a deviation or waiver from a normative reference for the specific case, then“Requirements validation” can be used to substantiate the request.


104 The documentation shall demonstrate assured safety and reliability in the context of system interfacesand external action.

105 It is the responsibility of the sub-system suppliers to provide the required documentation to the “Systemintegrator”.

106 With reference to Ch.1 Figure 3, the provisions in sub-sections B to E are applicable to defined subsystems.

Guidance note:An overview of recommended documentation for generic types of technical systems can be found in DNV-RP-A201‘Plan Approval Documentation Types – Definitions’.

The DNV service documents are available at http://www.dnv.com/resources/rules_standards/index.asp.


B. Rope Units

B 100 Fibre rope unit

101 The fibre rope unit utilised in “Deepwater deployment & recovery systems” shall comply with DNV-OS-E303, which provides the technical requirements and documentation requirements for fibre rope includingterminations with termination hardware.

B 200 Wire rope unit

201 The same principles to assuring safety and reliability apply to steel-wire rope units in a “Technologyqualification” process for “Subsea deployment & recovery systems” and to steel-wire rope units in a“Technology qualification” process for “Hang-off deployment & recovery systems”.

Guidance note:More specific requirements and references pertaining to steel-wire rope can be included in a later version of thisstandard and the preceding draft.


B 300 Hang-off fibre rope assemblies

301 Fibre rope assemblies utilised in “Hang-off deployment & recovery systems” shall comply with DNV-OS-E303, which provides the technical requirements and documentation requirements for fibre rope segmentsand termination hardware.

B 400 Condition management

401 The rope unit shall be accompanied by a condition management programme.

402 That condition management programme shall specify how input from service will be used in order toassure the safety and reliability of the system.




Guidance note:It is possible to adopt a qualification strategy by which service experience will be utilised to successively build upconfidence where evidence may be lacking for qualification to a service context, which is gradually expanded as moreexperience is gained.


403 The condition management programme for the rope shall be tightly allied to the condition managementprogramme for the rope guiding path, and that of the termination for external interface to the suspended mass.

404 Due consideration shall be given to rope unit storage.

B 500 Rope performance in the service context

501 The elements from the Rope Performance Description shall be linked to the Functional Description ofthe Underwater Deployment & Recovery System. The functional description shall explain how failure modesare controlled.

502 It shall be explained how operating procedures, condition management and marine operationsrequirements that define the service context contribute to rope safety and reliability.

B 600 Technology qualification and rope performance

601 The qualification documentation (evidence and argument) for the rope should be compiled into a “Ropeperformance description”.

602 The “Rope performance description” should describe the relationship between tension (on the rope),bending and twisting (of the rope) and load sharing (within the rope).

Guidance note:For the fibre rope unit the Rope Performance Description shall be according to DNV-OS-E303.


603 The important parameters shall be related to the functional description of the “Underwater deployment& recovery system”, which shall explain how the failure modes are controlled.

604 The control with failure modes can be substantiated in part by boundary conditions that are defined inthe “Service context” documentation for the system.

B 700 Generic failure modes for the fibre rope unit

701 A summary of failure modes for “Fibre rope unit” sub systems is provided in Appendix C for thefollowing key interfaces:

702 The overview is not exhaustive and it will depend on type and variant of system.

703 Other interfaces such as water column and external objects shall be duly considered.

Guidance note:The failure modes shall be accounted for in the assurance case for qualified technology, which will include that theyare reflected in the condition management program.

Summaries of generic failure modes for “Wire rope unit” and “Hang-Off fibre rope” assembly sub systems can bereflected in later versions of this standard and in the preceding drafts.


C. Mechanical Lifting Appliance

C 100 General

101 The mechanical lifting appliance shall comply with DNV Standard for Certification No. 2.22 – Chapter 2.

102 The system interface with fibre rope can be qualified by means of a strategy as illustrated in principle inCh.1 Figure 6.

Guidance note:DNV Standard for certification No. 2.22 does not cover fibre ropes.


— Mechanical lifting appliance (System interface)— Suspended mass (External interface)



D. Power and Control Systems

D 100 Power systems101 The power systems shall comply with DNV Standard for certification No. 2.22 – Chapter 2.

D 200 Control systems201 Control systems shall comply with DNV-OS-D202 ‘Automation, safety, and telecommunicationsystems’.

Guidance note:DNV Standard for certification No. 2.22 references Ship rules Pt.4 Ch.9 ‘Control and monitoring systems’, whichdoes not constitute requirements under this standard for “Underwater deployment & recovery systems”; howevercompliance to Ship rules Pt.4 Ch.9 should be considered for the vessel, as applicable.


202 The system interfaces with the mechanical lifting appliance shall be duly addressed.

E. Software Systems

E 100 General101 It is recommended to follow the recommendations of DNV-RP-D201 ‘Integrated software dependentsystems’.102 Whether the “Underwater deployment & recovery system” is software dependent or software redundantshall be demonstrated in the qualification documentation.

Guidance note:‘Software dependent’ implies that the system can fail to provide critical functions if the software fails. ‘Softwareredundant’ means that despite a potential software failure the system will still deliver required critical functions.


E 200 Software dependent systems201 “Underwater deployment & recovery systems” that are software dependent shall comply with DNV-OS-D203 ‘Integrated Software Dependent System (ISDS)’.202 The interface with the control system shall be duly addressed.




CHAPTER 3

CLASSIFICATION AND CERTIFICATION

CONTENTS PAGE

Sec. 1 Classification................................................................................................................... 30Sec. 2 Certification .................................................................................................................... 31Sec. 3 Technology Qualification ............................................................................................... 35Sec. 4 Marine Operations .......................................................................................................... 36App. A Certificate Example ........................................................................................................ 37App. B Argumentation in Qualification Strategy........................................................................ 38App. C Qualifying the Fibre Rope Unit for Deepwater Deployment & Recovery Systems....... 41App. D Graphical Presentations .................................................................................................. 45



SECTION 1CLASSIFICATION

A. General

A 100 General101 The principles, procedures, applicable class notations and technical basis for classification of offshoresupport vessels are given in the DNV Rules for classification of ships. Part 1 Chapter 2 gives the overview ofall class notations. Part 5 Chapter 7 covers special service or ship type notations relevant for such vessels.

Guidance note:The DNV service documents are available at http://www.dnv.com/resources/rules_standards/index.asp.





SECTION 2CERTIFICATION

A. Introduction

A 100 General

101 This section describes the work process that will take place when “Underwater deployment & recoverysystems” are certified by DNV according to the requirements of this standard. It is attempted to give thesechapters a chronological order such that the prerequisites for certain steps or milestones may be readilydetermined. The requirements are found in Chapter 2.

102 The following provisions apply in conjunction with certification according to this standard.

A 200 Main elements in certification

201 The main elements in certification of “Underwater deployment & recovery systems” are:

— certification of system integration— certification of sub systems.

202 The certification of system integration consists of system integration verification and assembly andintegration survey after the certification of the sub systems.

203 Sub systems shall be ordered with appropriate DNV certification at the supplier.Guidance note:For example, certification of the “Fibre rope unit” (sub system to integrated “Deepwater deployment & recoverysystem) consists of approval of manufacturers for yarns, rope and termination hardware according to the appropriateprogrammes of Standard for certification No. 2.9, design verification and fabrication surveys according to DNV-OS-E303.


A 300 Approval of manufacturer

301 For “Deepwater deployment & recovery systems” the loadbearing yarn, fibre rope and terminationhardware shall be manufactured at works which have been approved by DNV according to Standard forcertification No. 2.9.

302 For the other types of systems, manufacturers’ approvals shall be in place as required by the applicablestandards.

Guidance note:In order to be approved, the manufacturer shall demonstrate and submit documentation to the effect that the necessarymanufacturing, testing and inspection facilities and procedures are available and are supervised by qualifiedpersonnel. The manufacturer shall also carry out a test programme and submit the results. Approved manufacturersare published on DNV Exchange at http://exchange.dnv.com/tari.


A 400 Overview of the certification process

401 In the following, the work process is described. The process for certification of the integrated“Underwater deployment & recovery system” consists of the following main steps in chronological order:

— Request for system certification.— Pre-process meeting.— Submittal of documentation for approval.— Design verification of system integration.— Issuance of system integration design verification report.

— Requests for sub-system certification.— Design verification of sub systems.— Issuance of sub-system design verification reports.— Production and survey of sub systems.— Issuance of sub-system certificates.

— Integration survey.— Issuance of system integration certificate.

An example of a certificate for the integrated system is shown in Appendix A.


http://exchange.dnv.com/tari


A 500 Timelines501 Due time shall be allowed for DNV’s Responsible Approval Centre (RAC) to perform designverification prior to any procurement or production.

Guidance note:Any challenges pertaining to timeline to ensure completion of design verification so that time-critical procurement orproduction processes can commence shall be addressed and brought to the attention of DNV in the request forcertification.


502 Sufficient time shall be made available for the survey and other activities associated with the certificationprocesses.

A 600 Inspection release notes601 Inspection release notes will not be issued as part of the certification processes for “Underwaterdeployment & recovery systems”.

A 700 Confidentiality701 DNV will handle confidential information according to contract under which work is performed.702 Any special confidentiality concerns shall be raised in the “Request for certification”.

Guidance note:Claims that confidential information cannot be made available for design verification, or that survey should berestricted, will not be accepted by DNV, and will be taken as statement that there is no desire to obtain certification.


B. Service Context

B 100 Introduction101 In order to certify “Underwater deployment & recovery systems”, the verification includes thedesignated service context for the “Underwater operations”, as defined by:

— System operating procedures.— Condition management program.— Marine-operations boundary conditions inferred by the integrated system.

B 200 Operation of “Underwater deployment & recovery systems”201 The operating procedures for the Underwater Deployment & Recovery System will be certified as partof the system certification according to this standard, on behalf of the System Integrator.

B 300 Condition management programme301 The condition management programme for the “Underwater deployment & recovery system” will becertified on behalf of the “System integrator” according to this standard as part of the system certification.

B 400 Marine operations requirements401 Marine-operations boundary conditions inferred by the integrated system shall be stated in a separatedocument subject to the design verification of system integration.

C. Certification of the Integrated System

C 100 Roles, responsibilities101 The roles and responsibilities for “User”, “System integrator” and “Independent verifier” are given inChapter 2.102 DNV’s Responsible Approval Centre (RAC) will assume the role of “Independent verifier”, and willissue a design verification report based on the documentation provided by the “System integrator”, whichincludes information provided by the “User”.103 Pending the design verification report, the required survey activities and receipt of sub-systemcertificates, the local survey station will issue the system certificate.

C 200 Request for certification201 The request for system certification should be sent by the “System integrator” to DNVs local surveystation by e-mail.



Guidance note:Local survey station means the DNV office covering the site of system integration assembly and testing.


202 The following information should be included in the initial request for certification:

— user— system integrator— suppliers of sub systems— user requirements— scope of delivery and timeline:

— type of winch— type of rope unit:

— rope construction— type of loadbearing material— type of coating and performance characteristics.

— testing facilities, location and foreseen testing schedule— status with respect to certification of sub systems, and approval of manufacturers— any requests for deviations or test waivers, fully documented— overview of qualification argument and expected timeline for finalisation— status with respect to “Qualification of new technology”— condition management programme.

Guidance note:Reference is made to Ch.2 Figure 1 for an illustration of possible chains of responsibility for the various roles. It isforeseen that the role of “System integrator” is typically assumed by a winch manufacturer, whereas the role of “User”can be assumed by the owner of the vessel where the system is installed. It will be possible that a company in the roleof “User” also take the role of “System integrator”.


D. Sub-system Certification

D 100 General

101 Due time shall be allowed for DNV’s Responsible Approval Centre (RAC) to perform designverification for the individual sub systems as required by the respective DNV standards prior to anyprocurement or production.

Guidance note:The DNV service documents are available at http://www.dnv.com/resources/rules_standards/index.asp.


D 200 Fibre rope unit

201 Fibre rope units will be certified according to DNV-OS-E303.202 Request for certification shall be made by the rope manufacturer according to the work process definedin DNV-OS-E303, Chapter 3.

D 300 Wire rope unit

301 Wire rope units will be certified according to requirements that will be determined on a case-by-casebasis by DNV’s responsible approval centre.302 Request for certification shall be made by the “System integrator” as part of the request for systemcertification, see above.

D 400 Fibre rope assemblies

401 Fibre rope assemblies for use in “Hang-off deployment & recovery systems” will be certified accordingto DNV-OS-E303.402 Request for certification shall be made by the rope manufacturer according to the work process definedin DNV-OS-E303, Chapter 3.

D 500 Mechanical lifting appliance

501 The mechanical lifting appliance will be certified based on Standard for certification No. 2.22 – Chapter 1.




502 The provision of Standard for certification No. 2.22 – Chapter 1 concerning “Inspection release notes”is not applicable under this standard.503 Request for certification shall be made by the sub system manufacturer to the local survey station.

D 600 Power systems601 The power systems will be certified based on DNV Standard for certification No. 2.22 – Chapter 1.

D 700 Control systems701 Control systems will be certified based on DNV-OS-D202 ‘Automation, safety, and telecommunicationSystem” (DNV-OS-D202) – Chapter 3.

D 800 Software systems801 The software systems in software-dependent “Underwater deployment & recovery systems” will becertified based on DNV-OS-D203 ‘Integrated Software Dependent System (ISDS)’ – Chapter 3.

E. Recertification

E 100 General101 Used “Underwater deployment & recovery systems” may be re-certified for continued or prolongedservice according to this standard.102 Cases which may warrant recertification can be:

— The certificate has expired and the service period of the system shall be extended.— The system has seen excessive loads or service duration compared to the design premise.— The “Underwater deployment & recovery system” has not been previously certified by DNV.— Elements of the “Underwater deployment & recovery system” have been damaged and need repair.

103 The requirements for re-certification will be determined by DNV’s Responsible Approval Centre (RAC)on a case-by-case basis.

Guidance note:When an “Underwater deployment & recovery system” is re-certified (for example in connection with repair or uponcertificate expiry) then the existing certificate will be updated with an endorsement. The endorsed certificate will statethe history of the system to the extent possible and the new validity of the certificate.




SECTION 3TECHNOLOGY QUALIFICATION

A. General

A 100 Technology qualification assistance101 DNV units that are not involved in design verification as part of the certification processes can assist withestablishment of documentation, test design, performance of testing or formulation of assurance arguments.102 Results or findings from technology qualification assistance will be provided to the client.103 This documentation can be part of the documentation under the responsibility of that client as defined inChapter 2.

Guidance note:This standard covers certification of “Underwater deployment & recovery systems” on basis of documentationsubmitted and performed survey. Technology qualification assistance can be provided by DNV on request,independently of the certification process, and is not mandatory in order to obtain system certification.




SECTION 4MARINE OPERATIONS

A. Marine Operations

A 100 Verification of “Marine operations” requirements101 DNV Marine Operations can verify compliance between the service context document ‘MarineOperations Requirements’ and the VMO Standard.

A 200 Marine warranty survey201 Marine operations can be verified by DNV’s marine operations based on the VMO Standard.

Guidance note:All the DNV offshore standards covering marine operation are referred to as the ‘VMO Standard’, which replaces‘DNV Rules for planning and execution of marine operations’.This standard covers certification of “Underwater deployment & recovery systems” on basis of the conditions definedby the service context. Verification of marine-operations boundary conditions defined for the system, or warrantysurvey of marine operations performed with the system can be provided by DNV on request, independently of thecertification process, and is not mandatory in order to obtain system certification; however it is recommended.



Offshore Standard DNV-OS-E407, October 2012Ch.3 App.A – Page 37

APPENDIX A CERTIFICATE EXAMPLE


Offshore Standard DNV-OS-E407, October 2012Ch.3 App.B – Page 38

APPENDIX B ARGUMENTATION IN QUALIFICATION STRATEGY

A. Establishing an Assurance Case

A 100 General

101 This section provides supplementary information on the establishment of an assurance case.

102 The assurance case is an effective tool for:

— Expressing complex interrelations between claims, arguments and qualification evidence.— Facilitating definition of qualification activities shown in Ch.1 Figures 2 and 6.— Facilitating test design by formulating expectations to the test results in the complete setting.— Structured qualification documentation.

103 The claims identified during the technology and threat assessments (of the basic “TechnologyQualification” process) are organized in an assurance case that builds the justification to provide confidencefor the stakeholders.

104 The principle of an assurance case is shown in App.B Figure 1. Both the argument and the qualificationevidence are needed to justify that safety and reliability can be claimed.

Figure 1 The anatomy of an assurance case.

105 An argument without supporting evidence is unfounded, and therefore unconvincing.

106 Evidence without an argument is unexplained.

107 Arguments can be based on sub-claims that in turn can be based on more specific sub-claims, until hardevidence exists or can be provided by testing or analysis.

108 The GSN community standard /1/ provides suggestions for how to establish assurance cases, withemphasis on graphical presentation. Reference is made to Appendix D.

Guidance note:Graphical presentation of the assurance case as provided by GSN /1/ or KAOS /2/ is not mandatory under thisstandard, however it is recommended for the sake of precision and overview.


B. Qualification Strategy

B 100 General

101 This section provides supplementary information concerning application of a step-wise strategy to“Technology Qualification”. Here, strategy means that instead of aiming for complete, initial qualification forthe full service context, the qualification effort and the service context are balanced out in “TechnologyQualification” stages such that implementation to service can happen sooner, or at lower cost compared to thebasic “Technology Qualification” process.



102 A staged qualification strategy will be particularly useful when evidence that can be obtained afterimplementation has impact on the argument, or even the technology itself.

C. Simplification by Qualification Strategy

C 100 General

101 One main reason for working out a qualification strategy is the need to break down the complexity of thetasks and to gain experience as soon as possible. Thus, the establishment of a qualification strategy very muchbecomes a question of simplification, and in this light the following questions should be asked whenestablishing the qualification strategy.

— What do we need to document before the system can be used for the first time, with additional restrictions?— What defines first time use; which operations can be performed then?— What is the level of detail needed in the “Rope performance description”?— Is the system dependent or redundant of control systems or software?

The answers to the above simplification questions should be analysed with respect to type of mechanical liftingappliance, type of rope unit and type of loadbearing material and coating. It will then be possible to developthe details of the argument for how to qualify the rope unit as part of the integrated “Underwater deployment& recovery system”.

D. Characterisation of System Variants for DDRS

D 100 General

101 In order to establish the qualification strategy for a specific “Deepwater deployment & recovery systemit should be characterised with respect to (system) variant.

102 There are five key technologies in a “Deepwater deployment & recovery system” that uses fibre rope.The key technologies exist in categories:

— the type of mechanical lifting appliance:

— friction pull winch— direct pull winch.

— the type of rope:

— braided arrangement of strands— helical arrangement of strands.

— the type of fibre:

— characterised by stress rupture— characterised by creep failure.

— the coating on filaments, yarns and strands— type of termination:

— spliced— socket— other type.

103 The type and characteristics of the rope coating should be allied to the type of mechanical liftingappliance due to the fundamentally different means of providing the pulling action.

Guidance note:

Types of rope for DDRS do not include parallel-subrope tethers which can be used in “Hang-off deployment &recovery systems” that do not involve bending over sheave or drum under operating tension. Reference is made toCh.1 Figure 1.




E. Test Design

E 100 General101 The process for qualification of new technology sets requirements for how testing is defined andperformed. The way testing should be defined and performed is governed by the requirements for thequalification evidence as inferred by the argument, and by the timeline by which evidence is needed. The costof testing is also important and may have significant bearing on the resulting strategy.102 Test design in qualification programmes will depend on the strategy and available time for the first,incremental qualification and certification.

Guidance note:The appropriate qualification strategy will be tightly allied to the type and variant of “Underwater deployment &recovery system”.Methods for definition of testing in alternative qualification strategies for system types and variants can be reflectedin later versions of this standard or in DNV-RP-E305 and in the preceding drafts.Spare part philosophy should be included in the qualification strategy.


103 The available timeline may, in turn, have significant bearing on the possibility to perform tests whichaffects the qualification strategy as well as the assurance argument.


Offshore Standard DNV-OS-E407, October 2012Ch.3 App.C – Page 41

APPENDIX C QUALIFYING THE FIBRE ROPE UNIT FOR

DEEPWATER DEPLOYMENT & RECOVERY SYSTEMS

A. Qualifying the Fibre Rope Unit

A 100 Introduction

101 The objective of a technology qualification program is to show that the technology will be safe andreliable under certain conditions.

102 For compliance to this standard, an assurance case approach is required in order to substantiate that thetechnology qualification has been adequately performed to render the system safe and reliable for a definedservice context.

103 For the “Deepwater deployment & recovery systems” the fibre rope unit represents the part of the systemwith the most elements of new technology, where the qualification effort has to be focused.

104 The objective of the technology qualification will be to balance the service context with availablequalification documentation (evidence and argument) as illustrated in App.C Figure 1.

Figure 1 Using the service context to balance the technology qualification.

105 For the purpose of illustration, App.C Figure 1 indicates that the resulting operation time will besomewhere between the two extremes:

— Use the system once and then discard the rope unit.— Use the system for 10 years without any maintenance or monitoring of the rope unit.

Guidance note:The actual service life shall be substantiated by the solidity of the assurance argument and available evidence for thatparticular rope unit, and not by the perceived quality or resemblance to another rope unit that either looks nice orreputedly performs well in the application.


A 200 Approaches

201 Successful qualification of the fibre rope unit involves description of how it behaves.

202 In the following the qualification of the fibre rope unit is discussed on basis of a certain approach.

203 It is important to note that there are many viable routes to qualifying the fibre rope unit in a “Deepwater

Evidence

Argument

Claim

System Robustness

Assurred Operation Time

How to balance condition, use scenario and operation time?

Technology Assurrance Activities

Extreme No. 1:Use the system for 10 years without any inspection or maintenance

Extreme No. 2:Use the system once and then discard it



deployment & recovery system”, which may or may not include the definitions of critical parameters andfailure modes that are mentioned below.

Guidance note:The distinction between various approaches can be reflected in later versions of this standard and in the precedingdrafts.


B. The Performance of Fibre Rope Units

B 100 General101 The largest, general uncertainties for “Deepwater deployment & recovery systems” are currentlybelieved to pertain to:

— The performance of the fibre rope unit in repetitive bending, including coating durability.— The ability of the system to curtail peak tensions.— How the shape of the rope changes.— Change-in-length performance.— Torque and twist characteristic.

Guidance note:The second point will depend on whether passive or active heave compensation is being used, and the principles bywhich the control system operates.The inertia of the moving parts governs the aggregate phase difference through the mechanical lifting appliance. Thephase difference through the fibre rope and added mass are equally important.


C. Critical Parameters

C 100 Introduction101 In the following a discussion is provided on critical parameters relating to the failure modes for the fibrerope unit. It will be the objective of the system design – with the associated service context – to at all timesmaintain sufficient margin against failure.102 Critical parameters can be defined as:

— local stresses in the rope— temperature in the rope— time under tension.

103 The combination of tension, time, wear and temperature will need to be within the boundary conditionsset in the qualification basis.104 The “Rope performance description” can be based on the testing or modelling which is performed toaddress the critical parameters.

Guidance note:The following questions should be addressed for fibre rope units:

— What is the limiting temperature, and how is the margin to the critical temperature defined?— What is the limiting local stress, and how is the margin to the critical stress defined?— What happens to local stresses when the rope is twisted?— What happens to local stresses when the rope is bent?— What is the limiting amount of twist?




D. Failure Modes

D 100 Introduction

101 Generic failure modes that can be exerted on the Rope Unit by the system interface with the mechanicallifting appliance (including the rope guide path) are:

— Overloading— Time dependent failure— Processes pertaining to bending— Twisting— Kinking— External wear.

102 Generic failure modes from external action by the Suspended Mass are:

— Twisting— Concentrated bending at the termination— Failure of termination, e.g. the spliced eye.

D 200 Overloading

201 Overloading occurs when the rope is loaded to break, or to a tension resulting in a very short failure time.Overloading occurs when the local stresses in the rope are too high.

D 300 Time dependent failure

301 The time dependent failure modes in fibre rope are related to time under tension and processes thatreduce the load-carrying area of the rope:

— Stress rupture or creep failure— Wear and loss of area.

In a fibre rope not only the magnitude of a high tension is of importance, but also the time under sustainedtension. Reference is made to DNV-RP-E305.

D 400 Processes pertaining to bending

401 A general concern for “Underwater deployment & recovery systems” is how long the rope will last inrepeated bending. Repeated bending can occur when using heave compensation; or it can occur over time, asthe rope is extended or retracted. Heave compensation is of highest concern, as sufficient margin against failureneeds to exist in the prevailing operational condition. When the rope is bent over a sheave, the structure of therope is affected:

— The rope geometry is altered— Internal movement occurs between strands in the rope— The geometry of individual strands in the rope are altered— Internal movement occurs between yarns in the strands— Coatings may diminish due to localized pressure or environmental conditions.

Bending may be concentrated, typically at the termination of the rope unit.

402 In a fibre rope under tension, the above effects may result in the following processes:

— Transfer of loads between strands— Wear between strands due to sliding or scissoring— Generation of heat between strands— Wear internally in strands— Generation of heat internally in strands— Splice slippage.

D 500 Twisting

501 In principle, the processes inside the rope caused by twisting are similar to those for bending; only theactions on the interfaces are different. Twisting may occur over a long length of rope, or concentrated in a localspot. Further distinction – which will be rope construction dependent - should be made as part of the rope designprocess.

D 600 External wear

601 External wear occurs when there is relative movement between the rope and an external surface.



E. Interaction between Failure Modes

E 100 General101 Interaction between failure modes implies that the detrimental effect of two failure modes that occursimultaneously is different from the sum of the detrimental effects of each failure mode acting alone.102 It shall be substantiated that interaction between failure modes is managed through qualification testingand argument as part of the technology qualification documentation for safety and reliability within the servicecontext.

Guidance note:Due to the complexity of the issue, disallowing failure mode interaction that aggravates progression of damage maybe favourable in the earlier phases of a long-term qualification strategy.



Offshore Standard DNV-OS-E407, October 2012Ch.3 App.D – Page 45

APPENDIX D GRAPHICAL PRESENTATIONS

A. Presenting Arguments Graphically

A 100 Introduction101 An argument is used to link evidence to the claim in an assurance case demonstrating that a technologyis qualified.102 The claim represents the high-level goal for technology qualification in service context. 103 In order to link this goal to the evidence, it is necessary to define lower-level goals (sub-claims) thatimply the parent goal is met. This results in a logical hierarchy that can be presented in a goal tree.104 Graphical notations can be used to document the elements of the argumentation and the relationshipbetween these elements. Graphical documentation of assurance cases can be achieved using for example GoalStructuring Notation (GSN) /1/ or KAOS /2/.105 Assurance cases can be developed both top-down and bottom-up. The chosen strategy depends on thestate of the evidence.106 A bottom-up approach may be taken with basis in pre-existing evidence. This approach could howeverlead to the preferred claim on the top being impossible due to lacking evidence supporting the justification forthe claim. A top-down approach may be taken with basis in the claim that needs to be substantiated. Therequired evidence needed to underpin the argument will be a derivative of the top claim and the justificationthrough the argument. 107 Top-down and bottom-up strategies will need to be combined. The required evidence may overlapevidence needed for showing compliance with requirements from prescriptive standards which can simplifythe gathering of evidence.

B. Goal Structuring Notation (GSN)

B 100 General101 GSN is a notation for graphical presentation of assurance-case arguments. GSN explicitly documents theelements and structure of an argument, and the argument’s relationship to evidence. GSN is described in astandard /1/.102 In GSN, the claims of the argument are documented as goals and items of evidence are documented insolutions. 103 Strategy elements can be used to explain the reasoning between a goal and its sub goals.104 Context elements should be used to define the context in which the argument shall be interpreted.105 Assumption and Justification elements are used to explicitly document assumptions and justificationsmade in the argumentation.106 The example in App.D Figure 1 uses the GSN notation.


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ument by adressing gies to avoid kinks

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Argument by adressing stragies to limit temperature

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igure 1 xample of graphic presentation using GSN.

G12

Reliability Risk: 'Rope looses structural integrity' is sufficiently mitigated

S7Argument by addressing failure mechanism leading to lost of structural integrity in fiber rope unit .

G14

Failures due to Internal wear are sufficiently avoided

G15

Failures due to local tension, are sufficiently avoided

G16

Failures due to global tension, caused by tensile loads near strength load for a prologed period of time, are sufficiently avoided

G17

Rope tolerates permissible twist

A

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Acceleration between failure modes due to interaction is not sufficiently known therefore a XXX approach is selected.

S14

Argument by addressing strategies to avoid internal wear

S15Argument by addressing strategies to avoild local tension above limiting value

S16Argument by adressing strategies to avoid prolonged tension near strength load

G20

Local stress level below limiting value

G21

Time to failure for rope is more than enough

S117

Argument based on ropemodel for relationship stress distribution and twisting/bending

S118

Interaction between failuremodes is not permitted

Co2

Permissible twist is ....

S17

Argument by adressing stragies to withstand permissible twist

S1

Argstra

J1

This is the JIP phase 1 approach to enable fast implementation

Offshore Standard DNV-OS-E407, October 2012Ch.3 App.D – Page 47

C. Kaos

C 100 General101 KAOS is a notation for goal models that have been adapted for the purpose of assurance caseformulation. KAOS origins from requirements engineering and follows the structure of a combined success/fault-tree. 102 Goal decomposition in KAOS is performed by using “AND” and “OR” operators to show either the casewhere several sub-goals together contribute to the satisfaction of the parent goal, or where alternative goalsexist. The de-composition can be either full or partial. Full de-composition means that a parent goal has beencompletely refined and that no more sub-goals will be added to the de-composition, whereas partial de-composition means that more sub-goals may be added in the future.103 Obstacles prevent the satisfaction of the parent goal. There are different types of obstacles, e.g. hazardsthat obstruct safety goals and threats that obstruct reliability goals. Obstacles are further broken down usingsub-obstacles in a tree similar to a fault tree. Obstacles can be mitigated by goals that describe countermeasures.104 Through the goal model environment assumptions can be described using ‘domain’ properties. These arestatements that are expected to hold regardless how the system behaves.105 Goals are met by lower-level goals until substantiated by hard evidence.


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Rope looses structural integrity due to more

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Rope loosesstructural integrity

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Rope looses not structural integrity

due to high temperature

Rope looses not structural integritydue to more severe

kinks than permissible

igure 2 xample of graphical presentation using KAOS.

Ropes looses structural integrity

Rope looses structural integrity

due to external wear


due to internal wear


due to too high local tension

Rope looses structural integrity due to global

tension caused by tensile near strength load for a

prolonged period of time


due to external wear

Acceleration between failure modes due to interaction is not sufficiently known therefore a simplified approach is selected


due to internal wear


due to too high local tension

Rope looses not structural integrity due to global tension

caused by tensile near strength load for a prolonged

period of time

Rope has structural integrity

Documents

Os-E407