While on my recent trip I was doing a lot of talking about Test Driven Development and Agile approaches in general. One night I was having dinner with someone and I was introducing him to Eliyahu Goldratt and his Theory of Constraints.

In his book The Goal, Goldratt sets the framework for his theories using a novel about Alex Rogo who manages a plant where things are always behind schedule. Anyway, in one part of the novel, Alex takes his son's scout troop on a hike. The older kids start out in the front of the line, and the line begins to spread out - making it hard for the parents to keep track of things. He suggests that they have the younger kids go to the front, and the line stays tight - because the slower children are in front and things adjust to the "constraint".

Since I'd been speaking so much about TDD, it suddenly hit me that TDD may be another example of the Theory of Constraints. In typical waterfall approaches, you have testing largely happening at the end of the process. With TDD, you get a portion of the testing (the code coverage hits, unit tests) at the front of the process - yes, you take some more time early, but it lets the whole team hit a regular cadence and continue to improve over time as refactoring occurs.

Anyway, I thought that was interesting. FWIW, I did a quick search to see who else may be talking about this - only found one thing at the agile alliance. I have to dig into this more...