The article I found this week was written by two individuals working for Nokia Networks. They were involved in training product development staff in agile practices. Vodde and Koskela (2007) discussed Nokia’s environment for the past decades and their experiences in introducing test-driven development into the organization. The implication in the article is that because of the size and amount of retraining necessary to move toward agile development, Nokia is adopting agile practices a piece at a time (small bites) versus dropping the waterfall approach entirely and throwing the development teams into a completely new and unfamiliar situation. Vodde and Koskela also point out the benefit they found in using hands-on instruction for TDD versus lecture-based education.

The authors make a few observations during the time they were teaching TDD to experienced software developers. One important observation was, “TDD is a great way to develop software and can change the way you think about software and software development, but the developer’s skill and confidence still play a big role in ensuring the outcome’s quality.” The exercise the authors used in their course was to develop a program to count lines of code in source files and tests to verify the program’s operation. Each session would add a new requirement in the form of a new type of source file. The students were forced into an evolutionary/emergent situation in which the design had to change a little as the current and new problems of each requirement were solved. What the students’ speculated as a design at the beginning and what they actually ended with were different. The authors conclude with some recommendations for successful TDD adoption with other agile practices or as an isolated practice in a legacy environment:

  1. Removing external dependencies helps improve testability
  2. Reflective thinking promotes emergent design
  3. A well-factored design and good test coverage also help new designs emerge

Reference

Vodde, B., Koskela, L. (2007). Learning Test-Driven Development by Counting Lines. IEEE Software. 0740-745907.