PPT Slide
Chpt 11: Plan to Throw One Away
Building a pilot model or a pilot system is an intermediate step between the initial system implementation (or prototyping) and the final large-scale system.
Building a pilot model is necessary in order to overcome the difficulties unforeseen when going from a small-scale project to a large-scale project.
The pilot system should be thrown away and should not be given to the customer as a final model. This is because the pilot model often has bugs in it and would reduce the customer's confidence in the producer.
Software Maintenance:
- The major difference between software maintenance and hardware maintenance is that in hardware maintenance we simply repair or replace components and the architecture and the interface to the user doesn't change.
- However, in software maintenance we make design changes to the software and typically add new functions and because of this, the interface to the user changes.
- Also, in software maintenance, fixing the problems and new functions also introduce new bugs which requires further testing.
- What typically happens is that as we add more functions, we are adding more bugs which in turn requires more fixes and modifications. Therefore, software maintenance is a very difficult job.