22 November 2009

Fowler’s tech debt quadrants.

Mr Fowler refelcts on tch debt and comes up with a four quadrant moel to eaborate his thinking.

The two dimensions are prudence and intent. Which means is it based on good judgement, and did you mean to do it. The four quadrents are thus;
  • Q1 Reckless and intentional - maybe appropriate for short term band-aids that need to be implemented yesterday, or possibly your last day at work (but not on my team!)
  • Q2 - Reckless and unintentional - where a lack of skills is quietly (or not so quietly) creeping up on the developers.
  • Prudent and delibeate – decisive decisions to defer a best practice implementation in favour of a shorter term win – such as a release date.
  • Prudent and inadvertent – the situation when you look back after a project and see a better way to have done things.
What does this model give us for management and planning decisions on projects? It's a way of describing why things take time and why not just any team can be assigned to a software project.  You need the right mix of skills, both in design and execution.

In some ways this model reminds me of the Johari Window from the 1950's.

The difference here is the Johari window's perspectve is based on the perceptions of others.


  1. I like it. Looks like another tool one can use while conducting "Lessons Learned" meeting.


  2. That's a good idea. Thanks for the sugegstions.