Software Engineering for Students A Programming Approach

320 Chapter 24 ■ Incremental development
Summary
The aim of incremental development is easier bug detection. The mechanism is
incorporation of components one by one. Incremental methods include:
■ top-down
■ bottom-up
■ middle-out
■ use case based.
Use case based development provides early and frequent functionality. This in turn
means:
■ improved confidence by the client and the developer
■ the opportunity for the user to change their requirements
■ the opportunity for the user to decide what should be implemented next.
Use case based development also reduces the work of creating test drivers and
stubs.
• Exercises
24.1 Draw up an incremental process model for preparing a meal, including buying the
ingredients and washing up afterwards. Don’t forget to identify the product at each
stage.
24.2 Draw up an incremental process model for writing a student assignment. The assignment
is to write an essay reviewing the process models that are explained in this book.
The non-incremental approach is:
Step 1 read and digest all the relevant chapters
Step 2 write the review.
24.3 Draw up an incremental process model for a large civil engineering project, such as
building a road bridge across the channel between England and France. Identify
similarities and differences between this project and a large software development
project.
24.4 Create an outline plan for developing each of the systems in Appendix A, using an
incremental approach.
24.5 Compare and contrast the following approaches to development:
■ top-down
■ bottom-up