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1Department of MCA, NIT, DURGAPUR 9

SOFTWARE ENGINEERINGSOFTWARE ENGINEERING

LECTURER 3LECTURER 3


Prototype ModelPrototype Model -- IterativeIterative

listento

customer

build/revisemock-up

customertest-drivesmock-up

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Prototype ModelPrototype Model IterativeIterative Cont..Cont..

Advantage:Advantage:

Systematic approach.Systematic approach.

Risk can be controlled.Risk can be controlled.

Fit for absolute new system as well as Generic Software.Fit for absolute new system as well as Generic Software.

DisadvantageDisadvantage ::

Takes few year to publish the final prototype ultimately.Takes few year to publish the final prototype ultimately.Customer & users loose their interest to get the final prototypeCustomer & users loose their interest to get the final prototypeif prototype iteration exceeds.if prototype iteration exceeds.

The developer often makes implementation compromises inThe developer often makes implementation compromises inorder to get a prototype work quickly.order to get a prototype work quickly.


Rapid Application Development (RAD) ModelRapid Application Development (RAD) Model Iterative ModelsIterative Models

businessmodeling

datamodeling

processmodeling

applicationgeneration

testing&

turnover

businessmodel ing

datamodel ing

processmodel ing

appl icationgeneration

testing&

turnover

businessmo d e lin g

d a tamo d e lin g

p ro c e s smo d e lin g

applicationg e n e ra t io n

testing&

turnover

team #1

team #2team #3

60 - 90 days

RAD Model emphasize anextremely short developmentcycle. It is High Speedadoption of SDLC. Ifrequirements are wellunderstood & project scopeis constrained, RAD enablesa development team to createfull functioned system within

very short period of time.

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RAD ModelRAD Model Cont..Cont..

Business ModelingBusiness Modeling

The information flow among the business subsystems are modeled.The information flow among the business subsystems are modeled.

Process study.Process study.

Requirement study & Basic analysis.Requirement study & Basic analysis.

Data ModelingData Modeling

Define the DATA OBJECTS responsible for business information flDefine the DATA OBJECTS responsible for business information flow.ow.

Characteristic & Relationships between the data objects.Characteristic & Relationships between the data objects.

Process ModelingProcess Modeling

Define the FUNCTIONS responsible for business information flow aDefine the FUNCTIONS responsible for business information flow and Businessnd BusinessData Transformation.Data Transformation.

Process description are created for adding, modifying, deletingProcess description are created for adding, modifying, deleting & retrieving a Data& retrieving a DataObject.Object.



Application GenerationApplication Generation

RAD assumes the use of FOURTH GENERATION techniques.RAD assumes the use of FOURTH GENERATION techniques.

RAD process works to REUSE program components (when possible) aRAD process works to REUSE program components (when possible) and / ornd / orCreate REUSABLE program component (when necessary).Create REUSABLE program component (when necessary).

Automated tools are used to facilitate the construction of the sAutomated tools are used to facilitate the construction of the software (Tools Likeoftware (Tools LikeVISUAL STUDIO).VISUAL STUDIO).

Testing & Turn overTesting & Turn over

Many components may reused, so already been tested. Testing mayMany components may reused, so already been tested. Testing may be short.be short.(Reduction of time).(Reduction of time).

New components and all interfaces must be tested.New components and all interfaces must be tested.

Methodology must be fixed to Deploy, Implementation & MaintenancMethodology must be fixed to Deploy, Implementation & Maintenance of thee of thesoftware.software.

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Advantage:Advantage:

Systematic approach.Systematic approach.

Fit for Customized Software as well as Generic Software.Fit for Customized Software as well as Generic Software.

Parallel development is possible. So Project time is controllabParallel development is possible. So Project time is controllable.le.

Reusability of developed component is possible.Reusability of developed component is possible.


For large project RAD requires sufficient human resources.For large project RAD requires sufficient human resources.

For absolutely new project where building the new module,For absolutely new project where building the new module,components are problematic, RAD will not work there.components are problematic, RAD will not work there.

RAD is not appropriate when technical risk is very high. HeavyRAD is not appropriate when technical risk is very high. Heavyuse of new technology & high degree of interoperability withuse of new technology & high degree of interoperability withexisting computer program create these risk.existing computer program create these risk.


Spiral ModelSpiral Model Evolutionary ApproachEvolutionary Approach

Originally proposed by Boehm.Originally proposed by Boehm.

It couples the Prototype model with the controlled & SemanticIt couples the Prototype model with the controlled & Semanticaspect of the SDLC.aspect of the SDLC.

It provide potential for rapid development with incremental verIt provide potential for rapid development with incremental versionsionof the software.of the software.

During the early iterations, the incremental release might be aDuring the early iterations, the incremental release might be a

prototype. During later iterations increasingly more complete veprototype. During later iterations increasingly more complete versionsrsionsof the engineered system produced.of the engineered system produced.

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Spiral ModelSpiral Model Cont..Cont..

CustomerCommunication

Planning

Construction & Relea seCustomerEvaluation

Engineering

Risk Analysis

ABCD

A = Concept Development

B = New ProductDevelopment

C = Product Enhancement

D = Product Maintenance


Spiral ModelSpiral Model Cont..Cont..Advantage:Advantage:

Systematic and realistic approach to the development of largeSystematic and realistic approach to the development of largescale Software as well as new software.scale Software as well as new software.

Fit for Customized Software as well as Generic Software.Fit for Customized Software as well as Generic Software.

Use prototyping as a risk reduction mechanism.Use prototyping as a risk reduction mechanism.

Developer are enable to apply prototype approach at any stageDeveloper are enable to apply prototype approach at any stageof time.of time.

Reusability of developed component is possible.Reusability of developed component is possible.


Difficult to convince customers that the evolutionary approachDifficult to convince customers that the evolutionary approach isiscontrollable.controllable.

If major risk any uncovered, the problem will undoubtedly occurIf major risk any uncovered, the problem will undoubtedly occur..

The model is slow like LCDM.The model is slow like LCDM.

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Still Other Process ModelsStill Other Process Models

Component based modelComponent based modelthe process to apply whenthe process to apply whenreuse is a development objectivereuse is a development objective

Concurrent process modelConcurrent process modelrecognizes that differentrecognizes that differentpart of the project will be at different places in the processpart of the project will be at different places in the process

Formal methodsFormal methodsthe process to apply when athe process to apply when amathematical specification is to be developedmathematical specification is to be developed

Documents

3.Models