Sad Lec22_Notes_cocomo,Cmmi and Case Tool

7/28/2019 Sad Lec22_Notes_cocomo,Cmmi and Case Tool

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Capability Maturity Model

Integration


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Capability Maturity Model Integration (CMMI) is

a process improvement approach whose goal isto help organizations improve their performance.

CMMI can be used to guide process improvement

across a project, a division, or an entire

organization.

CMMI in software engineering and organizational

development is a process improvement approach

that provides organizations with the essential

elements for effective process improvement.

CMMI is registered in the U.S. Patent andTrademark Office by Carnegie Mellon University.

According to the Software Engineering

Institute (SEI, 2008), CMMI helps "integrate

traditionally separate organizational functions, setrocess im rovement oals and riorities, rovide


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3

CMM developed by the Software Engineering

Institute to help

organizations which develop software

to improve their software processes organizations which acquire software

to assess the quality of their contractors


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4

Immature organization processes are improvised during the course of a

project to resolve unanticipated crises

products often delivered late and their qualityis questionable

Mature organization organization-wide standard approach to

software processes, known and accepted by all

engineers focus on continuous improvement both in

performance and product quality


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The organization

Does not have an environment for developing and

maintaining software.

At the time of crises, projects usually stop using all

planned procedures and revert to coding and testing.


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Effective management process having established

which can be

Practiced

Documented Enforced

Trained

Measured

Improvised


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Standard defined software engineering and management

process for developing and maintaining software.

These processes are put together to make a coherent

whole.


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Quantitative goals set for both software products and

processes.

The organizational measurement plan involves

determining the productivity and quality for all important

software process activities across all projects.


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Emphasis laid on

Process improvement

Tools to identify weaknesses existing in their processes

Make timely corrections


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Organizational Innovation and DeploymentCausal Analysis and Resolution

5 Optimizing

4 QuantitativelyManaged

3 Defined

2 Managed

Cont inuous

Process

Improvement

Quanti tat ive

Management

Process

Standardization

Basic

Project

Management

Organizational Process PerformanceQuantitative Project Management

Requirements DevelopmentTechnical SolutionProduct IntegrationVerificationValidation

Organizational Process FocusOrganizational Process DefinitionOrganizational TrainingIntegrated Project Management for IPPDRisk ManagementIntegrated TeamingIntegrated Supplier ManagementDecision Analysis and ResolutionOrganizational Environment for Integration

Requirements ManagementProject PlanningProject Monitoring and ControlSupplier Agreement ManagementMeasurement and AnalysisProcess and Product Quality AssuranceConfiguration Management

Quality

Productivity

Risk,

Rework1 Initial

Process AreasLevel Focus

None


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COCOMO is one of the most widely used

software estimation models in the world

It was developed by Barry Boehm in 1981

COCOMO predicts the effort and schedule for

a software product development based on

inputs relating to the size of the software and

a number of cost drivers that affect

productivity


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COCOMO has three different models that

reflect the complexity:

the Basic Model

the Intermediate Model

and the Detailed Model


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Organic Mode Relatively small, simple software

projects Small teams with good application

experience work to a set of less thanrigid requirements

Similar to the previously developedprojects

relatively small and requires littleinnovation

Semidetached Mode

Intermediate (in size and


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Embedded Mode

Software projects that must bedeveloped within a set of tighthardware, software, and

operational constraints.


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Primary cost driver is the number ofDelivered Source Instructions(DSI) / Delivered Line Of Codedeveloped by the project

COCOMO estimates assume that theproject will enjoy good managementby both the developer and thecustomer

Assumes the requirements

specification is not substantially


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Basic COCOMO is good for quick,early, rough order of magnitudeestimates ofsoftware costs

It does not account for differences inhardware constraints, personnel

quality and experience, use ofmodern tools and techniques, andother project attributes known to havea significant influence on software

costs, which limits its accuracy


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E=ab (KLOC or KDSI)bb

D=cb (E)db

P=E/D

where E is the effort applied in person-

months, D is the development time in

chronological months, KLOC/ KDSI is the

estimated number of delivered lines ofcode for the project (expressed in

thousands), and P is the number of people

required. The coefficients ab, bb, cband db

are given in next slide.


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Software project ab bb

cb

db

Organic 2.4 1.05

2.5 0.38

Semi-detached 3.0 1.122.5 0.35

Embedded 3.6 1.20

2.5 0.32


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M o d e E f f o r t S c h ed u l e

Organic E=2.4*(KDSI)1.05

TDEV=2.5*(E)0.38

Semidetached E=3.0*(KDSI)1.12

TDEV=2.5*(E)0.35

Embedded E=3.6*(KDSI)1.20 TDEV=2.5*(E)0.32


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Its accuracy is necessarily limited because

of its lack of factors which have a

significant influence on software costs

The Basic COCOMO estimates are within

a factor of 1.3 only 29% of the time, andwithin a factor of2 only 60% of the time


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We have determined our project fits thecharacteristics ofSemi-Detached mode

We estimate our project will have 32,000Delivered Source Instructions. Using the

formulas, we can estimate:

Effort = 3.0*(32) 1.12 = 146 man-months

Schedule = 2.5*(146) 0.35 = 14 months Productivity = 32,000 DSI /

146 MM= 219 DSI/MM

Average Staffing = 146 MM /14months


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Software engineering tools consisted solely

of translators, compilers, assemblers,

linkers, loaders, etc.

the software NEEDEDto build code.

Computers werent powerful enough or

advanced yet to support higher-levelfunctioning


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Software engineering often follows specific

standardized methods

There are lots of diagrams anddocumentation involved

So now computers can be used to deal with

the higher-level aspects of softwareengineering


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What is a CASE Environment?

CASE is the use of computer-based

support in the software development

process.

What is a CASE Tool?

A CASE tool is a computer-basedproduct aimed at supporting one or more

software engineering activities within a

software development process.


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Supply basic functionality, do routine tasksautomatically

Be able to support editing of code in the particularprogramming language, supply refactoring tools

Enhance productivity

Generate code pieces automatically

Increase software quality

Intuitive use

Integration with other tools

For example, code editor works with code repository


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Project management software

System design tools

Code storageCompilers

Translation tools

Test software


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Code generation tools (Visual

Studio .NET)

Code analysis (Borland Audits)Development of data models

(UML editors)

Cleaning up code (refactoringtools)

Bug tracker


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CASE tools do more than just output

code

Can be used to generate SE documents

Database schema

Data flow diagrams

Entity relationship diagrams

Program specifications

User documentation


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UpperCASE: Tools for the analysis and

design phase of the software

development lifecycle (diagramming

tools, report and form generators,analysis tools)

Lower CASE: Tools to supportimplementation, testing, configuration

management

Documents

Sad Lec22_Notes_cocomo,Cmmi and Case Tool