Rapid Application Development (rad) n174o

Visual Programming Rapid Application Development (RAD)

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Waterfall (Vs RAD)  Longer Time  More Documentation  Larger Teams  More Internal development (Less outsourcing)  Less Flexibility in changing path/scope

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Prototyping  What is a prototype?  - A model with certain appearances and behaviors to the finished product, while lacking in some of the features

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Prototyping Initial Analysis

Define objectives

Specify

Prototyping completed

Evaluate

Construct

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Prototyping  What is a prototype ? 1. Throwaway prototyping 2. Evolutionary prototyping

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Throwaway Prototyping  Build prototype  Evaluate and decide changes  Discard (throwaway) prototype  Build new (more) improved prototype  Continue the above process till a Complete version satisfying all / most of the requirements is built 6

Evolutionary Prototyping  Build prototype  Evaluate and decide changes  Modify the prototype into a new (more) improved prototype  Continue the above process till a Complete version satisfying all / most of the requirements is built 7

Prototyping (vs. RAD)  Discuss  (Which of the two types of prototyping are most similar to RAD?)  (Why is the other type not like RAD?)

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Incremental Development  The Spiral Model

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Incremental Development (Vs RAD)  Four phases :1.

2.

3. 4.

Inception determined scope and purpose of the project Elaboration-requirement capture and determine structure of the system Construction – building the software (s/w) Transition - installation

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The Unified Software Development Process  Four phases:1. Inception-determine scope and purpose of project 2. Elaboration-requirement capture and determine structure of the system 3. Construction – build s/w 4. Transition - installation

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RAD - Introduction  RAD is a software development process allowing the to build a usable system within a short period of time

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Reasons to use RAD  Discuss 1.

Good reasons -

2.

Bad Reasons –

(RAD Prerequisites – good time mgt. skill, good

cost mgt. skill) 13

Main Features of RAD  Timeboxing (the most critical feature)  Quality (very critical – cannot avoid) 

Also important in all other methodologies

 Iterative evolutionary prototyping 

Iterate (Repeat) until done

 Hybrid Teams – about 6 people 

Developers, Fulltime s, others….

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Main Features of RAD  JRP – t Requirement Planning  JAD – t Application Development

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RAD Constraints  “Fitness for Business Purpose”  Informal Deliverables 

Paper prototypes rather than informal deliverables

 Less than 6 months

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When RAD works / Fails  RAD works better when :

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

Application – Standalone Performance and Reliability - Not critical Project Scope Constrained

 RAD fails when :

  

Application interoperate with other programs Products – Mass market No high-end IS tools Product is Life or Time critical

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