Plan-Do-Check-Act is the key learning cycle that is at the foundation of lean thinking. But how do you make a good plan, and more specifically, how do you estimate how long the tasks in the plan will take?
If you have historical data, or you can accurately estimate the work content, the task of estimating task duration is very straightforward. But if you are doing something you have never done before, estimating the task duration can be very challenging.
Fortunately, agile project managers have developed a clever approach for this very challenge. It is called project planning poker. It was developed to address the challenging problem of estimating how long it will take software developers to complete coding tasks. Here is how it works:
Step 1: Each of the developers is given a set of Project Planning Poker cards (see Figure 1).
Step 2: The task whose duration is being estimated, is discussed.
Step 3: Each participant privately selects the card which represents their best estimate for how long it will take to complete each task.
Step 4: Participants reveal their choice for the task. If consensus is reached, they record the result and move on to the next task. If consensus has not been reached, they discuss and try again.
The elegance of this approach is that it is fast and easy. It harnesses the wisdom of the participants. It is based on relative measures, i.e., a task that is given a 40 will take twice as long as a task that is given a 20. (The absolute duration of each task can be determined by actual data. That is, teams will need to record how many points they estimated for each tasks and then measure how long each task took. A conversion factor between points estimated and actual task duration can then be constructed.)
Agile project managers have found this approach to be helpful because they are constantly asked to estimate how long it will take to do something they have never done before. And lean practitioners are often faced with that very same challenge. They may need to estimate how long it will take to dramatically improve a production line’s layout or develop standardized work to enhance patient flow or complete a kaizen newspaper item. In each of these cases, there may be very little historical data to estimate the task durations. But, an agile approach may be exactly what you need.