Thursday, December 4, 2008

Snake on the wall!

We found ourselves in a retrospective and there was a general feeling that there were a lot of interruptions in our day caused by "other people" outside the team. Nobody could put their finger on it and everyone had different unique examples. We couldn't easily say if we handle this problem or group of people then it will stop.

So how do you handle this?

Invoke the Snake on the Wall!

Every time a team member feels as though a task they are responsible for is delayed, they write it down on a post-it note. The note includes the time lost (compared to if they didn't have the delay), the thing affected, the cause, and their initials. They take the note and add it to the "end of the snake" which is a growing row of notes on the wall.

Over time the snake is monitored for repetitive patterns. The issues consuming the most productivity time are prioritized to the top of the list for the manager, scrum master, and team to focus on reducing or removing. Scrum masters look at it daily, managers look at it weekly (or when it grows suddenly), and the team reviews it right before retrospectives to trigger new topics. When an item is solved, those related stickies are removed from the snake and it is collapsed back down (you can't let it grow infinitely, otherwise you demoralize the team).

What does this accomplish?
  • it validates real issues
  • it kills false beliefs and misdirected complaints
  • it quantifies the impact of impediments
  • it creates transparency for managers who don't believe what you say
  • it empowers the team
  • it is immediate
  • it self-prioritizes
  • it uncovers surprises
On my last team we quantified for upper management how much time was lost EVERY DAY due to a bad source control system we were forced to use. It also provided insight into things we would never have thought were a problem. If used properly, it does a good job of quantifying the ongoing costs of certain types of technical debt.

So, I'm trying it a second time with my new group. We'll see how it goes.


  1. Update: We had our first retrospective since implementing the snake. It went really well! We reflected on when we should add things to the snake, looked at what it was telling us, and focused on 4 main topics in it.

    I feel as though the retrospective was more effective because of the snake because our conversations were focused on impediments causing real time losses or frequent issues instead of what our memories told us.

  2. Yeah, Martine's "Waste Snake" is a great idea. I really thought it helped with a few different situations now.

    It also helped make my case for trimming down the number of branches we maintain. When people realized we were losing over a man week per week to version management, it wasn't that hard of a sale.

  3. Nice post, Kevin! You wouldn't happen to have a photo of your wall with the snake that you could post with this entry?

  4. I don't. I just collapsed the snake down for our retrospective two days ago... but maybe I'll remember to take a pic right before the next one when it is really long again.

    Just imagine a row of winding post-it notes on the wall... it's not all that glorious, just effective.

  5. I love this idea. It fits so nicely with the whole Agile and Lean space - kind of a value-stream technique. The theory is important but I really like it when I find an extremely practical application of it. The snake will definitely feature at our shop in future.

  6. Interesting... problem / countermeasure boards are another way to deal with this issue:

  7. Kevin:

    Just want to let you know that the "pain snake" (that's what I call it) has been very useful to the agile teams I have coached. So useful, in fact, that I included it (with credit to you) in my book, Coaching Agile Teams, as a way to help the team reveal their own problems. Thanks for this simple and powerful technique.


  8. Thank you Lyssa, I may have to pick your book up to see that!