I am the blog of Hal Fire, and I bring you…

… interesting tidbits of release engineering.

Kaizen the low tech way

On Jan 29, I treated myself to a seminar on Successful Lean Teams, with an emphasis on Kanban & Kaizen techniques. I’d read about both, but found the presentation useful. Many of the other attendees were from the Health Care industry and their perspectives were very enlightening!

Hearing how successful they were in such a high risk, multi-disciplinary, bureaucratic, and highly regulated environment is inspiring. I’m inclined to believe that it would also be achievable in a simple-by-comparison low risk environment of software development. ;)

What these hospitals are using is a light weight, self managed process which:

  • ensures visibility of changes to all impacted folks
  • outlines the expected benefits
  • includes a “trial” to ensure the change has the desired impact
  • has a built in feedback system

That sounds achievable. In several of the settings, the traditional paper and bulletin board approach was used, with 4 columns labeled “New Ideas”, “To Do”, “Doing”, and “Done”. (Not a true Kanban board for several reasons, but Trello would be a reasonable visual approximation; CAB uses spreadsheets.)

Cards move left to right, and could cycle back to “New Ideas” if iteration is needed. “New Ideas” is where things start, and they transition from there (I paraphrase a lot in the following):

  1. Everyone can mark up cards in New Ideas & add alternatives, etc.
  2. A standup is held to select cards to move from “New Ideas” to “To Do”
  3. The card stays in “To Do” for a while to allow concerns to be expressed by other stake holders. Also a team needs to sign up to move the change through the remaining steps. Before the card can move to “Doing”, a “test” (pilot or checkpoints) is agreed on to ensure the change can be evaluated for success.
  4. The team moves the card into “Doing”, and performs PSDA cycles (Plan, Do, Study, Adjust) as needed.
  5. Assuming the change yields the projected results, the change is implemented and the card is moved to “Done”. If the results aren’t as anticipated, the card gets annotated with the lessons learned, and either goes to “Done” (abandon) or back to “New Ideas” (try again) as appropriate.

For me, I’m drawn to the 2nd and 3rd steps. That seems to be the change from current practice in teams I work on. We already have a gazillion bugs filed (1st step). We also can test changes in staging (4th step) and update production (5th step). Well, okay, sometimes we skip the staging run. Occasionally that *really* bites us. (Foot guns, foot guns – get your foot guns here!)

The 2nd and 3rd steps help focus on changes. And make the set of changes happening “nowish” more visible. Other stakeholders then have a small set of items to comment upon. Net result - more changes “stick” with less overall friction.

Painting with a broad brush, this Kaizen approach is essentially what the CAB process is that Mozilla IT implemented successfully. I have experienced the CAB reduce the amount of stress, surprises, and self inflicted damage amongst both inside and outside of IT. Over time, the velocity of changes has increased and backlogs have been reduced. In short, it is a “Good Thing(tm)”.

So, I’m going to see if there is a way to “right size” this process for the smaller teams I’m on now. Stay tuned....

Pyevn & Tox Can Get Along

I fought this for quite a few days on a background project. I finally found the answer, and want to ensure I don’t forget it.


Activate all the python versions you need before running tox.

After I upgraded my laptop to OSX 10.10, I also switched to using pyenv for installing non-system python versions. Things went well (afaict) until they didn’t. All of a sudden, I could not get both my code tests to pass, and my doc build to succeed.

The error message was especially confusing:

pyenv: python2.7: command not found
The `python2.7' command exists in these Python versions:

Searching the web didn’t really shed any enlightenment. I’d find other folks who had the problem. I wasn’t alone. But they all disappeared from the bug traffic over a year ago (example). And with no sign of resolution.

Finally, I tried different search terms, and landed on this post. The secret – you can have multiple pyevn instances “active”. The first listed is the one that a bare python will invoke. The others are available as python*major*.*minor* (e.g. “python3.2”) and python*major* (e.g. “python3”)