1 Modeling System and Prototyping

2 Introduction  Techniques for gathering users’ requirements  should be used in early stage(s) of SDLC  Information acquired when prototyping:  user reactions  user suggestions  revision plan  innovations

3 Approaches to Prototyping  Kinds of Prototyping  Patched-Up Prototype  A workable system with all required features, but inefficient (e.g., poor records retrieval time)  Non-operational Prototype  A non-operational system, but has been implemented for testing some features  First-of-a-Series Prototype  Full-scale working system to test realistic interactions  Selected Feature Prototype  A workable system without some essential features  May be used as part of the actual system

4 Prototyping  An Alternative to SDLC?  Issues with SDLC  Lengthy development time required  Tend to result in high-cost development  Users ’ requirements can change before the process is completed  User never known their actual requirements until something tangible exist  Issues with Prototyping  Can meet small group ’ s requirements which may not be adequate for overall system

5 SDLC in Microsoft

6 Developing a Prototype

7 Guidelines for Developing a Prototype  Working in Manageable Modules  This is the main advantage of prototyping  Unimportant feature(s) can be left out  Building the Prototype Rapidly  Slow implementation will lead to the problem occurred with SDLC  Should be completed in 2-3 days!!  Rapid Application Development (RAD) tools are widely used

8 Guidelines for Developing a Prototype  Modifying the Prototype  Prototype normally requires several modifications  The prototype must be modifiable  Modules should not be highly interdependent  Stressing the User Interface  For users, interface is the system  Interface should lead to minimum training required

9 Disadvantages of Prototyping  Managing the project  Extending the prototyping indefinitely create problems  A plan for collecting, analyzing, and interpreting the feedback is necessary  Modifications to the problems should be completed in a short period of time  Adopting and incomplete system as complete  When badly needed, prototype seems to be an ideal approach, but it may lead to backlash!!

10 Advantages of Prototyping  Change the system early in the development process  Scrapping undesirable systems  A system can be built to really meet users’ needs and expectations

11 Users ’ Role in Prototyping  No users  No reason for prototyping!!  User is pivotal  System analyst must try to minimize inputting their own idea in prototyping process

12 Users Help Prototyping  Experimenting with the prototype  Users should be free to experiment  Analysts can observe their interactions  Giving open reactions to the prototype  Requires good analysts  users relationship  Suggesting changes to the prototype  Analyst must take all feedback seriously  This is the best for making any change!!