Software Architect's Handbook

Advantages of the bottom-up approach

One advantage of a bottom-up approach is the greater level of simplicity. The team only has to focus on individual pieces and builds only what it needs for a particular iteration.

This approach works well with agile development methodologies. With an iterative approach that handles change, refactoring can take place to add new functionality or to change existing functionality. Each iteration ends with a working version of the software until eventually the entire system is built. Agile practices, such as automated unit testing and continuous integration, are encouraged and can lead to higher quality software.

A bottom-up approach avoids the possibility of a big design up front, which can lead to overdesigning ...