up previous next contents
Next: Four Values Up: Introduction to Extreme Programming Previous: Four Variables   Contents

The Cost of Change

Under certain circumstances the exponential rise in the cost of changing software over time can be flattened. If the cost curve can be flattened, old assumptions about the best way to develop software no longer hold true.

Several factors make code easy to change, even after years of production:

  1. A simple design
  2. Automated tests
  3. Lots of practice in modifying the design

Next: Four Values Up: Introduction to Extreme Programming Previous: Four Variables   Contents