Escaping the Oubliette (Part 1a) – Debt Prevention

Reading time ~3 minutes

This is a partial re-post of Escaping the Oubliette (Part 1). I’ve split the article into smaller readable components.

Great, I’ve got my incoming defect strategy nailed,

Now how do I prevent defects and debt in new code?

In 5 words…

Continuous attention to technical excellence.

Here’s my top 7 (there are plenty more)

  1. Acceptance Criteria – Be really disciplined on your acceptance criteria & acceptance tests, team up with Analysts, Testers, Product Owners if you have them and attack your stories from every angle. A good approach to this is a “story kick-off” where the whole team dismantles a story before starting.
  2. Thinking Time – don’t just start coding right away, task things out, try the 10 minute test plan, discuss your approach with your peers and for more complex or large items, try the “just enough design” approach.
  3. TDD – It’s hard to start but has an immense impact.  I’ve just seen a team complete their first project using TDD. 3 weeks into their final round of post feature-complete testing, their defect run-rate hasn’t had the testing spike seen on prior projects. In fact they’re keeping on top of all new incoming defects and have time to start paying down the historic backlog.
  4. Pair Programming – Do it in half-day trial chunks if you don’t have the stomach for going full-tilt. I’ve performed remote pair-programming with colleagues across the Atlantic using decent phone headsets and online collaboration tools for hours at a time. The net result of 2 days of remote pairing was finding and fixing about 10 extra defects in a thousand lines of code that neither of us would have found coding alone.
  5. Peer reviews – there is still a huge space for these in agile teams. But here’s the thing. Be really tough. A peer review is not a hurdle. It’s a shared learning exercise. Functional correctness is actually the smallest component of a peer review. You should trust your developers that far. But there’s a whole series of other aspects to review. See the joy of peer reviews.
  6. Small tasks – I once worked with an outsourced team who when taking work would disappear into a hole for 2 weeks and return with a single task in our configuration management system containing edits to 200+ files and multiple condensed edits to the files. My rule of thumb is one reviewable task per activity. If you’re going to add new functionality and refactor, that’s 2 independent tasks that can be identified and reviewed separately. This means you should be able to easily deliver 2 reviewable, closable tasks per day.
  7. Fast Builds – make it insanely simple for a developer to perform an incremental build that validates new code against the latest main code line. (small tasks are a big help here).  This includes the right subset of unit and functional tests. Aim for a target of a 30 second response time or less between hitting the button and seeing the first results.

In the next article in this series I’ll focus on “Tailing” – How do you start reducing the old defects.

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