Plan-Do-Check-Act (PDCA)-powered learning

1st August 2010
Simon Baker

Deming‘s Plan-Do-Check-Act cycle is a scientific method for problem resolution. But it isn’t just about resolving problems in a timely fashion. Used properly it raises awareness of context in order to solve a problem by identifying and removing its root cause so the problem won’t recur and thus improve the long-term performance of the system.

Deming's Plan-Do-Check-Act cycle

First grasp the current situation to gain an understanding of the system and determine the problem with the current conditions. Go to the source and observe the problem to challenge assumptions, clarify the problem, and verify our mental image of how the system works. To be more objective we should study the system and the problem from as many viewpoints as possible. We always look at least from the perspectives of the business, its customers, and the product itself (the product has needs – it wants to be healthy, reliable, be used by customers, etc). And we look at the economics of the situation too.

Plan (Hypothesis)

Develop an hypothesis about the root cause. Without an hypothesis the approach is just trial-and-error and nothing will be learned. Devise countermeasures, i.e. changes to the system that will address the identified root cause. Design an experiment to implement the countermeasures. The experiment must include suitable measurements. These are used to visualize the future system state by defining explicit expectations for the countermeasures and, of course, measure the effects of the countermeasures to determine whether the system was improved.

Do (Experiment)

Conduct the experiment.

Check (Study)

Evaluate the results using the measurements we defined in the plan. Ask what was learned. By comparing actual results to expectations, we confront our assumptions in order to gain insight and validate our understanding is accurate. This is the step most people don’t do or don’t do well.

Act (Adjust)

If the results are satisfactory, we can incorporate the solution into system, e.g. if it’s a process change we make it the new standard way of working. Otherwise we adjust and take new action.

With organizations fixated on short-term results, people are driven to work around the problem or deal with it quickly and often clumsily. People usually take the visible and immediately obvious manifestation of a problem to be the actual problem and set out to resolve that. But it’s more than likely a symptom of something more deeply rooted. In which case the problem will recur.

We use PDCA repeatedly to root out the true causes of problems and systematically find and verify better ways of working. By running short experiments we are able to continually test our understanding for assumptions and gain insight. In effect, we are constantly learning.

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