In the RUP a development case is a tailoring of the RUP which defines how your project will approach its work. Every project is different, therefore you need a tailoring which reflects your situation. The development case will indicate which artifacts (such as use cases, a data model, a project plan, ...) you will create and potentially even the level to which you will create them.
For example, you can write use cases to various levels of details or styles, as I show in
Detailed Essential Use Case,
Informal System Use Case, and
Formal System Use Case.
The real trick, however, is to predict what your project will need to do before you do it. You get better at this over time with experience, and smart organizations develop what we call organizational-level development cases which reflect the needs of a category of projects within your org. These sorts of development cases are described in
The Enterprise Unified Process book.
- Scott
<a href="http://www-306.ibm.com/software/rational/bios/ambler.html" target="_blank" rel="nofollow">Scott W. Ambler</a><br />Practice Leader Agile Development, IBM Rational<br /> <br />Now available: <a href="http://www.ambysoft.com/books/refactoringDatabases.html" target="_blank" rel="nofollow">Refactoring Databases: Evolutionary Database Design</a>