Myths about PDCA
PDCA is a simple and powerful way of thinking. There is, however, some misunderstanding about its use. Yesterday I participated in a training session with some students and Lean teachers about how to use PDCA. These are some of the most interesting questions we discussed at the session:
- PDCA is for engineering: PDCA is great for solving technical problems. This does not mean that it can only be used for that. Things like “how to design a training session” or “how to create a robust communication plan” can be studied and implemented using PDCA. At the end of the day it is a structured way of establishing hypothesis and testing them.
- The “P” phase is over when you have a project plan: “P” (Plan) does not mean “create a to-do list”. The most important part of “Plan” is to establish a hypothesis and define a goal for your experiment. It is incredible how many “so-called PDCA cycles” are begun without knowing what you want to test. Therefore the tests will probably be useless or, in the best case, will provide very limited information. If you don’t have a goal, any direction is valid.
- The “A” phase does not look too important: “A” (Act/Adjust) provides the time to think about what you learned in your previous experiment. The “Act/Adjust” phase creates the learning cycle, links one experiment with the following one and increases dramatically the chances of success. If you don’t stop to think, you are not learning, you are just shooting in the dark.
- PDCA is about trying things and testing if they work: Well, yes, but this is only half of the work. If you just do things and check if they work, what you get are several DC (do-check) tests, not PDCA cycles. The difference is important at least in 2 ways:
- Do-Check skips “Plan” and jumps directly to “doing”, which is not a good strategy (see again bullet 2)
- Do-Check skips “Act/Adjust” and does not link experiments, which, again, is not a good idea (see again bullet 3).
- It’s so difficult to check if things have worked! This is typically a signal that the “Plan” phase is missing or has been done only partially (and remember, “no goal” means that anything is valid). Sometimes data is really difficult or even impossible to get. In that case use indirect metrics to determine success (for example, one can know if a training session has been fruitful if the number of operation errors decrease)
PDCA is a great friend for any improvement effort. Just use it with love.