Completion of a task is accomplished by performing a sequence of steps. The more steps in the sequence the more likely you are to make a mistake; either by forgetting a step or doing the step out of order. One method for reducing the likelihood of making a mistake is the creation of sub-tasks. This is where the analogy to dancing comes in to play.
When you first learn to dance you learn basic steps; the waltz’s box step, the tangos 8-count “Slow, Slow, Quick Quick Slow”… Once the basic step is mastered (and heaven help me one day I will master the box step) then additional “sub-tasks” can be learned. There are four virtues of sub-steps.
- Low chance of order mistakes: shorter tasks have a lower risk for errors due to their simplicity
- Low cost for errors: if a mistake is made in a sub-task it is, often, isolated to that sub-task and it can be quickly re-run
- Decomposition: frequently when broken into sub-tasks, the task can be distributed to multiple people.
- Ability to chain together: The sub-tasks can be decomposed into multiple “routines” and reused in multiple processes.
In general, processes that have 3 ~ 5 steps are considered “easy” to remember and master. Going above 8 steps in a process results in increased possibilities of human error.