Se Intro Sdlc

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Software is engineered, not manufactured.

Software Doesnt Wear outMost software are custom-build

Why is Software Different?


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Infant

mortalityWear out

Time

Hardware

Failure rate.


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LIST OF PROBLEMS

Role of Software :

Advances in Hardware outpace the software.

Cannot keep pace with the demand for new Software.

Struggle to build high quality and reliable software.

Ability to support and enhance existing programs is

threatened by poor doc and inadequate resources.


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LIST OF PROBLEMS

Industry Perspective :

Why does it take so long to get programs finished ?

Why are costs so high?

Why cant we find all errors before we give the

software to our customers ?


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LIST OF PROBLEMS

Ageing of S/W plant :

Even small changes can fail the S/W.

No one understands the internals.


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Why Projects Fail ?

Lack of clear & understandable specifications

Poor Documentation

Over Ambitious Objectives

Poor Communication


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The application of a systematic, disciplined,quantifiable approach to development, operation,

and maintenance of software; that is, the applicationof engineering to software.

IEEE Standard Computer Dictionary, 610, ISBN 1-55937-079-3, 1990

Definition of Software Engineering


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Why?

As a solution provider, you need to

understand why the customer is interested inyour solution.

Understanding of the context and

background of the customers request

Without this, you will not feel the

importance of the project/product.


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What?

What the customer is looking for?

Requirements and Analysis would cover this

in a formal way.

i.e. What solution will suit the purpose thanwhat you can do or would like to do.


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How?

How to implement? What are the methods

to be followed?

Follow a scientific way of implementing the

project/ developing the product.


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1. Project Startup - Concept, Proposal.

2. Requirements and Analysis.

3. High level Design.

4. Low level Design.

5. Construction - Unit test, Code inspection.

6. Integration and System tests.

7. Replication, delivery, installation.8. Acceptance Testing (Requirements mapped)

9. Maintenance (may involve all the above)

10.Project windup - Checklist, Report, Lessons learnt.

Phases of Software Development


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S D L C

Determine project scope

Secure project sponsorship

Define preliminary resources

Secure core resources

Scope complete

Scope


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How the customer explained it


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S D L C

Scope

Conduct needs analysis

Draft preliminary software specifications

Develop preliminary budget

Review software specifications/budget with team

Incorporate feedback on software specifications

Develop delivery timeline

Obtain approvals to proceed (concept, timeline,

budget) Secure required resources

Analysis complete

Requirements


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How the project leader understood it


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S D L C

ScopeRequirements

Review preliminary software specifications

Develop functional specifications

Review functional specifications

Incorporate feedback into functional

specifications

Obtain approval to proceed Design complete

Design


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How the system analyst designed it


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S D L C

ScopeRequirements

Design Identify modular/tiered design parameters

Assign development staff

Develop code

Developer testing (primary debugging)

Development


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How the programmer wrote it


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S D L C

ScopeRequirements

Design

Development

Develop unit test plans using product

specifications

Develop integration test plans using product

specifications

Unit Testing

Review modular code

Test component modules to productspecifications

Identify anomalies to product specifications

Modify code

Re-test modified code

Testing


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S D L C

ScopeRequirements

Design

DevelopmentIntegration Testing

Test module integration

Identify anomalies to specifications

Modify code

Re-test modified code

Testing (Contd)


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What operations installed


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S D L C

ScopeRequirements

Design

Development

Testing

Develop training specifications for end users

Develop training specifications for helpdesk

support staff

Identify training delivery methodology

(computer based training, classroom, etc.)

Develop training materials Conduct training usability study

Finalize training materials

Develop training delivery mechanism

Training


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S D L C

ScopeRequirements

Design

Development

Testing

Training

Develop Help specification

Develop Help system

Review Help documentation Incorporate Help documentation feedback

Develop user manuals specifications

Develop user manuals

Review all user documentation

Incorporate user documentation feedback

Documentation


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How the project was documented


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How the customer explained it


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How the project leader understood it


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How the system analyst designed it


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How the programmer wrote it


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How the Business Consultant described it


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How the project was documented


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What operations installed


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How the customer was billed


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How it was supported


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What the customer really needed


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Increasing quality Achieve conformance to requirements

reduce the number of software defects

mitigate risks associated with the software

Reducing project cost and schedule

provides a framework for systematic, incremental software process improvements reduces the cost and schedule of the testing, installation, and maintenance phases

Improving manageability enhanced accuracy of project planning

detailed means of tracking projects

early measures of software quality

improved repeatability of success stories

Benefits of SDLC

Documents

Se Intro Sdlc