Limitations of WSJF

Economics of Sequencing Development Appropriately

A few weeks ago I talked about WSJF (Weighted Shortest Job First) and how I apply it to my daily to do list. That continues to work when I use it, but it’s amazing how things fall apart when I travel. Planning gets rough, exercise gets rough, diet gets rough, sleep cycle gets rough. It goes on. Anyway, back to the topic. I’ve been using WSJF for both my personal task list and work and I’m beginning to see where it works well and it doesn’t.

The biggest issue with WSJF is that it assumes that each objective is pretty much independent of the other objectives that are being evaluated. It doesn’t account for interdependencies except in a very soft way in the time criticality and risk reduction/opportunity enablement columns. The two areas where this has come up are technical interdependencies and risk reduction strategies.

Technical interdependencies are pretty obvious. You can’t achieve a particular objective unless you first achieve another objective on the list. It doesn’t matter where it falls in the WSJF stack. My tactic for resolving this is after doing the WSJF sort to put the objective being depended on in the slot immediately above the objective that depends on it. Not a lot of experience with this so far, but it seems to be working.

Risk strategy is a bit more subtle. One way of reducing risk is to reduce the number of variables in the objective. Basically, the number of things that need to change in order for the objective to be realized. This plays out in a couple of ways: First in how you factor (break down into sub-objectives) your objectives. Second, in how you sequence those sub-objectives. How you do either of these depends upon a strategy since there may be multiple ways to factor and sequence that vary based on strategy. WSJF doesn’t account for strategies like this very well. I suspect the best way to approach this is to examine your list of objectives. If any are “watermelons” in the sense that they imply several changes at once to the current status quo then it’s probably a candidate for factoring and sorting. Discovering how to pick the best strategy from many is an interesting thing to ponder but I don’t currently have any tools in hand. Camparative WSJF may play a role here.

WSJF is a very valuable tool but as has been so often noted “The answer isn’t in the spreadsheet.” These are examples of where you may need to step outside of the WSJF process and modify the results based on additional information.


Prioritizing Your Life with WSJF

Economics of Serializing Develoment

Effective prioritization can be a challenge in any aspect of life. Simple linear sorted lists tend to encourage inconsistent prioritization criteria between any two items on the list. Weighted shortest job first (WSJF) teases apart a set of prioritization criteria then merges them back together again to create a prioritization that appropriately considers several factors that you may care about.

Last week I attended a class in Boulder, CO that enabled me to get my SAFe (Scaled Agile Framework) Program Consultant certification. I can now put the letters SPC after my name. Continue reading “Prioritizing Your Life with WSJF”