2.0 SLC Engineering

7/29/2019 2.0 SLC Engineering

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Announcements/ Reminders

FB group (IE 155 A.Y. 2012-2013)

Form 5 and class card

Index card/ picture

1/4 sheet (at least one per mtg)

Case study #1 on Monday, December 10


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Previously


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System Life-Cycle [Engineering]

M.A.Ramirez | December 04, 2012


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Objectives

Define system life cycle

Identify the phases of a system life cycle andactivities associated

Identify principles and approaches in designing forthe system life cycle

Identify problems in a system life cycle Enumerate some system process models


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Introduction

Last meeting .

Industrial engineers design industrial

systems

Few I.E.s really engage in overall systemdesign


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Introduction

Industrial engineers are systems engineers

Classical engineers has focused mainly on productperformance as the main objective rather on

development of the overall system of which the

product is a part

Accordingly, engineers must turn its focus on life-cycle engineering


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The System Life Cycle

Fundamental to application of systems design/engineering is understanding the system life-cycle

process illustrated for the product in the figure below


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The significance of focusing on the system life cycle is thatdecisions made early in the Acquisition Phase are informed of

the proposed and intended activities in the Utilization Phase(e.g. Maintenance and Operation, etc.)

A life cycle focus can save money in the long term

Sixty percent of the errors in system development originate in thesystems requirements analysis


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Classification is generic

Both the acquisition and utilization process may involve boththe customer and the producer

Detailed presentation of the elaborate technological activities

and interactions that must be integrated over the system life-cycle process is shown in your handout :)


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Progression is iterative from left to right, and not serial

Life cycle functions described and illustrated are generic

It is essential that this process be implemented completely,not only in the acquisition of new systems but also in re-

engineering of existing systems


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A. IDENTIFYING THE NEED/ CONCEPTUAL DESIGN

producing a clearly-defined set of user requirements at the

system level

clearly defining the functional requirements of the system

establishes a Functional Baseline (the whats and whys ofthe system)


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B. PRELIMINARY DESIGN Aim: convert the Functional Baseline into a preliminary definition of the

system configuration or architecture (the hows of the system)

The stage where functional design is translated into physical design

Result: Allocated Baseline -- indicates that the functional requirements

have been grouped together logically and allocated to subsystem level

requirements which combine to form the overall system design


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C. DETAIL DESIGN and DEVELOPMENT

Development of the individual subsystems and

components in the system

Prototyping, testing and evaluation

Product Baseline


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D. PRODUCTION and/or CONSTRUCTION

system components will be produced in accordance

with the detailed design specifications

Configuration audits


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E. PRODUCT USE, PHASEOUT, & DISPOSAL

Operational use and system support

Disassembly and disposal of elements or

components of the system without causingenvironmental degradation


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Systems engineering activities may continue to support

any modification activity that maybe required

rectify performance shortfalls

meet changing operational requirements or

external environment

enhance current performance or reliabilitymaintain ongoing support to the system


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Designing for the Life Cycle

Get sheet!

What is the meaning of designing within the

system life-cycle context compared to the old school

definition of design?


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Life-cycle focused design is simultaneously responsive tocustomer needs and to life-cycle outcomes

Design should not only transform a need into a definitiveproduct and system configuration

It should ensure the designs compatibility with relatedphysical and functional requirements


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System life cycle goes beyond the product life cycle

It embraces the life cycle of the manufacturingprocess as well as the life cycle of the product

support and service capability


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3 concurrent life cycles progressing in parallel


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Need for the product comes into focus first

During conceptual design of the product,consideration should simultaneously be given to its

production

This gives rise to a parallel life cycle for bringing amanufacturing capability into being


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3 concurrent life cycles progressing in parallel


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Third life cycle is of great importance too, but often

neglected until product and production design iscompleted

Needed to service the product during use and to

support the mfg capability during its cycle


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Communication and coordination is needed to develop theproduct, the manufacturing process, and the support

capability

Not easy to achieve

Progress in this area is facilitated by new technologies thatmake more timely acquisition and use of design information

possible


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Systems Engineering

Process Models


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Waterfall Process Model


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Waterfall Process Model

Introduced by Royce in 1970

Initially used for software development

Each phase is carried out to completion in sequence

until the product is delivered


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Vee Process Model


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Vee Process Model

Developed by Forsberg and Mooz

the Vee describes and models the technical aspectof the project cycle

Starts with user needs (upper left)

Ends with user-validated systems (upper right)


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Spiral Process Model


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Spiral Process Model

Developed by Boehm in 1986

Introduces a risk-driven approach for thedevelopment of products and systems

Iterative and proceeds through the several phases


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What the requirement stated. What the designer specified

What the programmers implemented What the user wanted

System Life Cycle Problems


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It leads to misunderstandings between users anddevelopers about what is to be delivered

The information used in one subsystem is frequently

needed by other subsystems

Systems grow and change


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The SDLC needs an integration stage that identifies all

inter-relationships

Every system is part of a larger system and can be

broken into smaller subsystem

The numerous components of a system mustcommunicate with each other


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The most specialized systems are the least adaptable

Slow, inflexible, people-intensive system that iscomplex and unresponsive to organizational needs


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Next Meeting

Quality function deployment; and/or Functional Analysis


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- END

Thank you!

Documents

2.0 SLC Engineering