The document discusses prototyping as a software development approach. It involves rapidly creating an initial version of the system (a prototype) to validate requirements with customers and refine them. The prototype may not include all functionality but allows users to experiment and provide feedback to improve the requirements. The process then iterates, revising the prototype based on this feedback until the final system is developed.

1. Prototyping
 SDLC approach
 Sample of system is prepared
 Comprehensive system
 Doesn't include all user requirements
 Based on evolutionary method

2. Prototyping
 Rapid software development to validate
requirements
 Help customers & developers understand
the requirements for the system
 Users can experiment with a prototype to
see how the system supports their work
 Prototype can reveal errors and omissions in
the requirements

3. Prototyping
 Considered as a risk reduction activity
which reduces requirements risks
 Used when all requirements cannot be
identified and freezed initially
 Throw-away model given to user
 On the basis of feedback, actual system
is developed

4. Prototyping
 Misunderstandings between software
users and developers are exposed
 Missing services may be detected and
confusing services may be identified
 A working system is available early in the
process

5. Prototyping
 The throw-away prototype should NOT
be considered as a final system
 Some system characteristics may have
been left out
 There is no specification for long-term
maintenance
 The system will be poorly structured
and difficult to maintain

6. Prototyping- 4 steps
1. Identify user’s basic information
requirements
2. Develop initial Prototype system
3. Use of Prototype system to refine
the user’s requirements
4. Revise & enhance Prototype system

7. Prototyping
Establish
prototype
objectives
Define
prototype
functionality
Develop
prototype
Evaluate
prototype
Prototyping
plan
Outline
definition
Executable
prototype
Evaluation
report

8. Prototyping- Step 1
1. Identify user’s basic information
requirements
 Form of outputs required from system
 Based on users’ expectations, cost of
workable prototype is calculated

9. Prototyping- Step 2
2. Develop initial Prototype system
 Users’ basic information requirements
 Minimum possible time
 Efficiency is not main consideration

10. Prototyping- Step 3
3. Use of Prototype system to refine
the user’s requirements
 User gains hand-on experience on
initially developed Prototype
 Further refinements done, if required

11. Prototyping- Step 4
4. Revise & enhance Prototype system
 Make necessary changes pointed by
user after using Prototype
 Steps 3 & 4 are repeated again & again
 Refined as per user’s satisfaction

12. Prototyping Process
Determine
Requirements
Requirements
Construct
Prototype
Prototype
Requirements
Adjustments
Demonstrate
Prototype
OK
System
Implementation

13. Prototyping Benefits
•Improved system usability
•Improved design quality
•Developers learn from customers
•Additional functionality neededPossible

14. Prototyping Benefits
•Improved maintainability
•Reduced overall development effort
•“Try Out” ideas in limited cost
•Functioning system into hands of user
quickly

15. Prototyping Benefits
•More Flexible
•Steady, visible signs of progress
•A more accurate end product
•Users are actively involved in the
development

16. Prototyping Benefits
•Errors can be detected much earlier
as the system is made side by side
•Quicker user feedback is available
leading to better solutions

17. Limitations
Customer may want the prototype
delivered
Process may continue forever- Scope
not well defined
May increase the complexity of the
system

18. When to use
Requirements are unstable
New, original development
Develop user-interfaces

19. When not to use
Requirements may change
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