SDLC Framework

Risks Rewards Goals Lifecycle comparisons Framework and Methodology comparisons How to implement Case study examples Q&A

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Introduction

RequirementsUnrealistic or unarticulated project goalsBadly defined system requirements

RiskUnidentified and unmanaged risksUse of immature technologyProject team not able to handle the project's complexitySloppy development practices

CommunicationPoor communication among customers, developers, and

usersPoor reporting of the project's statusStakeholder politics

Planning Inaccurate estimates of needed resourcesCommercial pressuresPoor project management

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Why do Large Projects Fail?

What and Why and WhenAnd How and Where and Who.

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What is SDLC – Simplified Version

Who wants it? Who will benefit? Who is going to do it? Who is going to pay for it?

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What is SDLC – Who

What do you want? What will it do? What will it impact? What benefit do you expect?

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What is SDLC – What

When do you want it? When is the contractual deadline?

When is regulatory implementation?

When is the market window of opportunity?

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What is SDLC – When

Where will it be built? In house Vendor Contractor On-shore or off-shore

Where will it run? In house Vendor Local implementation National or global implementation

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What is SDLC – Where

Why do you want it? Why do you think it will benefit us?

Why do our clients, customers, beneficiaries want or need it?

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What is SDLC – Why

How will you do it? Be very, very detailed.

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What is SDLC – How

WaterfallFountainSpiral(螺旋 )RAD/JADRapid Prototyping

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Life Cycle Comparisons

WaterfallAdvantages Linear and sequential Simplifies task scheduling – no overlapping steps Ensures points of review

Disadvantages Slow Does not adapt to changing

requirements Minimal user input Higher error rates

Planning

Analysis

LogicalDesign

PhysicalDesign

Implementation

Maintenance

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Fountain

Based on the waterfall model  

But observes that the sequence always contains cycles  

Reflects the fact that some phases cannot begin before others  and that some phases are poorly delineated  

A mental image to help visualize what actually happens in many real software development projects

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Spiral

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Spiral Categorizes the many (and repeated) phases

of software development into a number of cyclically repeated sectors 

System complexity and size grows with increasing radius, as do investment and risk

Disadvantages Difficult to convince some customers process

is controllable Needs considerable risk assessment If risk not discovered, problems will occur Risk analysis effort wasted for simple, easy

projects.

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Rapid Application Development (RAD)

Joint Application Development (JAD)

Advantages Heavy user involvement More accurate requirements Higher user satisfaction Rapid Application Development (RAD) is a

methodology for compressing the analysis, design, build and test phases into a series of short, iterative development cycles. This has a number of distinct advantages over the traditional sequential development model.

One of the principles of RAD is to start developing as early as possible in the project,

Disadvantages Hard to decide when its done 16

Rapid Prototypingrapid prototyping (RP) refers to a

class of technologies that can automatically construct physical models from Computer-Aided Design (CAD) data.

The steps are: Create a CAD model of the

design Convert the CAD model to STL

format Slice the STL file into thin cross-

sectional layers Construct the model one layer

atop another Clean and finish the model

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Rapid PrototypingAdvantages Iterative process Involves user in analysis and

design Captures requirements in

concrete(具體的 ) form Higher user satisfaction

Disadvantages Harder to estimate manpower

time Premature(過早的 ) launch of

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