Evolving the 8 Lean Wastes Snake

Written by: Francis O’Reilly, Scrum Master, Ammeon
The “Snake on the wall” technique is one that has been used by many Agile and Lean teams in various forms for many years. In its simplest form, the scrum master draws a snake’s head on a post-it on the wall, and as team members run into distractions, impediments and other frictions during the course of their work, they note it on another post-it, and join it to the head … further post-its attach to the previous, and so on, forming a snake body.
The length of the snake’s body gives an indication of how many problems there are at any moment. The scrum master collapses the snake down as the impediments are resolved.
A variant of this we tried in Ammeon was the 8 Lean Wastes Snake. Here, the Snake is drawn on a large poster in the team area. The snake is divided into 8 sections, one for each of the 8 Lean Wastes (the original 7 Lean Wastes + “Skills”):
  • Time
  • Inventory
  • Motion
  • Waiting
  • Overproduction
  • Overprocessing
  • Defects
  • Skills

As team members run into impediments, they place post-its on the appropriate section of the snake. The scrum master keeps an eye on any new issues appearing and attempts to resolve as appropriate; perhaps also presents back to the team at the retro how many issues of each type were logged this sprint, how many resolved, and how many remain.
Another benefit of the lean waste snake is that it can provoke interesting team discussion around addressing waste; I have used this to spur discussion of what types of waste our team encounters that would fit into the 8 categories, challenge the team to think of examples (hypothetical or real) for each category. I found this is very useful to help the team identify, and put a label on, the various friction and pain points they encounter; also as a “safety valve”.
Recently I had the opportunity to try introduce this technique to a non-software team who were on the beginning of their agile journey. They found the waste snake intriguing and worth discussing but ultimately a bit hypothetical, as they could not easily identify what section of the snake they should stick their post-its to. Also, they found the amount of space afforded to be quite limiting. For these reasons engagement with the Snake was slow and difficult.

So – we decided to iterate simpler and more user-friendly. Replacing the snake with a 2×4 grid, one box for each Waste, with written examples in each of that category of waste, and crucially, that the team helped contributed to themselves, as a reminder. Now we have lots more space for post-its, along with some written reminders of grounded examples relevant to them.

While engagement is still growing with the new Wastes Grid, going through the exercise of capturing the team’s own examples and a few reminders during the course of the sprint, helps capture and crucially visualise the current friction points.

Tags: , , , , ,