Prototyping Environment

1
Prototyping Environment

• Requirements for rapid application development

2
Prototyping

• It is easier to tell what you dont like about
  an existing system than to describe what you
  would like in an imaginary one
• A.M. Jenkins, 1983

3
Tactic

• Evolution
• Throwaway
• Life Cycle component

4
The Prototyping Process
Identify Initial Requirements
Use and Evaluate
Develop System
Iterate
Document and Install
5
Roles

• User Responsible for business solutions
• Intermediary Run system for user
• Builder Write code for application
• Technical Supports the development
  Support tools
• Toolsmith Build basic tool modules (often work
  for software houses)

6
Choice

• Life Cycle
• Prespecification possible
• Changes expensive
• Good project communication
• Static model OK
• Rigorous approach useful
• Iteration unacceptable

• Prototype
• Prespecification difficult
• Quick tools work
• Communications gap
• Animated model needed
• Rigor after requirements
• Iteration accepted

7
Factors Favoring Prototyping

• Structure interactive, on-line (OLAP)
• Logic structured but not algorithmic
• DSS applications are often data-report types
• User competent and active participant
• Time Constraint not a crash project
• Management willing to work with method
• Size not overly large or complex

8
Factors Favoring Prototyping

• Problem
• imprecise specifications,
• poorly defined communications,
• interactive model needed
• Why not use prototyping

9
Builders Added Value(Professional Design)

• Date and time stamps
• Control totals
• Audit trails
• Common interface feel
• Additional functions
• Testing

10
Prototyping Tactics

• Normalize data to 3NF
• Use component engineering
• Use existing components
• Assemble from existing parts
• Reuse pieces
• Create pieces so that they can be reused
• Cut and paste
• Keep a set of examples

11
Prototyping Tactics

• Use active data dictionaries
• Automate documentation
• Keep teams small
• Integrated software workbench tools
• Specify objectives not procedures
• Provide end-user report writing tools
• Use professional prototypers
• Have systems developers work with prototypers

12
Project Management

• Initial Model 2-6 weeks
• Must be fast enough to maintain interest
• Revisions immediate - 2 weeks
• Chargeback use charges to avoid frivolous
  changes
• Approval determine the group who approves
  iterations
• Sign off formal acceptance