Alternatives to the PPP
For my money, the PPP is the best method for creating classes and routines. Here are some different approaches recommended by other experts. You can use these approaches as alternatives or as supplements to the PPP.
Test-first development. Test-first is a popular development style in which test cases are written prior to writing any code. This approach is described in more detail in "Test First or Test Last?" in Recommended Approach to Developer Testing. A good book on test-first programming is Kent Beck's Test-Driven Development: By Example (Beck 2003).
Refactoring. Refactoring is a development approach in which you improve code through a series of semantic preserving transformations. Programmers use patterns of bad code ...