What Is Plan Do Check Act (PDCA)?

Sounds easy in principle, doesn’t it? Just plan your work and work your plan. So, why is “plan do check act” so difficult in practice? Using the Plan Do Check Act (PDCA) method is like climbing a hill: it starts out easy but gets harder the higher up you go. What Is Plan Do Check Act (PDCA)?

In short, PDCA is a four-step improvement loop. You plan what you want to achieve and how, do the work while recording what happens, check the results against the plan, and act on what you learned by standardizing what worked or correcting what did not. Then you start the loop again. The steps are simple to describe; the hard part is sustaining them, and that is what the rest of this article covers.

Plan Do Check Act Defined

It is known as PDCA for short and refers to the process approach of management or the learning loop of discovery. PDCA is basic quality. Start with a target (a target is the minimum plan) and work on getting closer to the target and staying on target. That is PDCA.

ASQ describes the plan-do-check-act cycle as a four-step model for carrying out change. The same loop is also called the Deming cycle, the Shewhart cycle, or PDSA (plan-do-study-act). According to The W. Edwards Deming Institute, the cycle was first introduced to Deming by his mentor, Walter Shewhart of Bell Laboratories. Whatever you call it, the loop only works if you repeat it.

Document Your “Plan”

The plan is really the easiest part of plan do check act. Start with goals that are measurable. Document your plan using objectives, policies, procedures, and forms. Assign individual responsibilities, and you’re done. When you’re building an ISO 9001 Quality Management System, this is not hard at all. But it gets harder, and pretty quickly.

What are examples of planning?

• Quality Plans, Control Plans, Safety Plans, Security Plans, Maintenance Plans
• Turtle Diagrams, Process Map, Flow Diagram, Value Stream Maps (VSM)
• Quality Policy, Mission, Vision
• Quality Objectives, KPI, Targets, Goals, Criteria
• Work Instructions, Procedures, Forms
• Risks, Opportunities, FMEA
• Training Requirements
• Equipment, gages
• Specs, CSR, Feedback
• Resource budgets

Using Your Plan Is the “Do” Part

What does the “Do” in plan do check act mean? This refers to using the policies, procedures, and forms to realize your objectives. This means collecting data, and populating your forms. You have to use your procedures and follow your policies.

While this may sound easy at first, keeping it up is the hard part. You may start with good intentions (that’s the “plan” part), but as they say, “Good intentions don’t pay the bills.” Your company has to follow through on its plan, and follow-through, or commitment, starts at the top. Furthermore, management commitment isn’t an isolated event; it’s part of the company philosophy.

What are examples of “Do”?

• Process Data
• Inspection records for inputs, in-process, outputs
• Sign-offs, signatures, Authorizations, Approval Dates
• Training records
• Gage records
• Maintenance records
• Nonconformance records

“Check” Your Data Against the Plan

In case you missed that, let me say it again: “doing” takes management commitment. That’s a large part of what makes plan-do-check-act so hard. As management, you get so involved in running the day-to-day aspects of the business that you forget that you started with good intentions (the plan). It is not that the plan was ill-conceived; it’s that there’s more to it than a piece of paper. Plans need continual reevaluation. You need to constantly “check” your progress and adjust the plan accordingly. What’s so hard about checking the plan?

In the “check” step of plan do check act, you have to convert data into information. Charting data can make this much easier but even so, a chart is just a visualization of data. A chart is not information without a target. In addition, you need enough data points to show trends. How many make a trend?

Two points make a line; you need at least three points for a trend. But how much confidence will you have in a three-point trend? Not much. Ten points would build confidence in your trend. Instead of the last three months, look at the last 13 weeks. It will give you more confidence in your trend. Formal run chart rules make the same point. The Institute for Healthcare Improvement run chart rules treat 5 or more sequential data points all going up or all going down as a trend, and 6 points when you have 20 or more data points in total.

What are Some Examples of “Check”?

• Trend/run charts
• Statistical Process Control (SPC)
• Data Analysis
• Effectiveness
• Comparisons to plan

Creating information from data requires what Deming called “profound knowledge” about your system. His System of Profound Knowledge ties together four areas: appreciation for a system, knowledge of variation, theory of knowledge and psychology. It will help if you understand a little about statistics, which will make it easier to separate individual data points that represent the “vital few” or significant ones from the “trivial many”. Creating information out of data is not easy; often, it requires that you continually dissect the data and look at it from many different points of view.

This is also why Deming himself preferred the word “study” to “check.” The Deming Institute notes that Deming emphasized the PDSA Cycle, not the PDCA Cycle, with a third step emphasis on Study, not Check. Checking asks whether you hit the number. Studying asks why, and what the result teaches you about the process.

“Act” On Your Results

So, let’s say you started with a good plan, you were able to collect some meaningful data, and you turned it into useful information. If you’ve accomplished this, the “Act” phase should be easy, right? Possibly, if you have a stable environment.

Today’s business world is an increasingly unstable environment. Old and new forces are continually changing the dynamic. There’s local and global competition, widespread and affordable technology, weather and climate, cultures, beliefs: a host of forces acting on your business.

What are Some Examples of “Act”?

• Corrective Actions Preventive Actions (CAPA)
• Improvements
• Changes/ Management of Change (MOC)
• Feedback sent

Management of change is more than good practice in some industries. OSHA’s Process Safety Management standard requires employers to establish and implement written procedures to manage changes to process chemicals, technology, equipment, and procedures for covered processes. Even where no regulation applies, a written change procedure keeps the “Act” step from becoming an undocumented workaround.

Deciding what to do to compensate for or leverage external forces has always been difficult; it’s just becoming more so. But if you do a good job at the first three phases, the “Act” phase of plan-do-check-act becomes a lot easier. You just need to make better information out of your data.

An Example of Plan Do Check Act in Action

The Olympics happen every few years. Some Olympic records, and a few world records, are broken over the course of the event. You watch these athletes perform and you marvel at their power, their endurance, their finesse.

How do they do it? What makes them so special? Are they that different from you and me? Are they superhuman? No, not really. They’re just like you and me, well, maybe not now. But we all start out on equal footing.

The big difference? With a few exceptions, the athletes got their start fairly early in life. And almost from the day they laced up a pair of skates or strapped on skis, they had an ambitious, long-range goal: to be a pro, maybe even the next Wayne Gretzky or Hermann Maier.

Family and friends encouraged and helped them. Their parents, and then their coaches, made up their plan. They knew that to get the big goal, these future stars had to accomplish a lot of smaller goals, and they had to do it in stepwise fashion.

The plan included competition, proper nutrition, and physical and mental training. Their coaches checked their performance in training and competitions. They analyzed the athlete’s performance, noted where they were reaching those small goals and where they weren’t, and revised the plan accordingly. Then, they executed the revised plan to improve performance.

They repeated this stepwise plan over and over until they reached their big goal, whether that was turning pro, making the Olympic team, making it to the medal round, or standing on the podium at the medal ceremony.

Think about that. They made a plan, executed it, checked their progress, and improved incrementally. What does that remind you of?

If you thought ‘Deming Cycle’, you’re right. Plan, do, check, and act, just like your organization should be doing (if it isn’t already). Your organization is just like that Olympic athlete. Improvement doesn’t happen overnight. It happens in stages, over time, following a plan.

Using the Process Approach to Create a Well-Designed Process

Consider this: What are your goals for the short and long term? Do you have a plan to get there? Are you satisfied with your performance? More importantly, are your customers?

How do you get better? What will it take to make your firm stand out from the rest, to get to the Games, to the medal round, and maybe even the gold, silver, or bronze?

Are you monitoring and analyzing your business performance in order to improve? Are you looking for overnight success, or are you looking for incremental improvement over time? Do you adjust your plan when you don’t meet your goals?

ISO 9001 builds this thinking into its requirements. Guidance from the ISO 9001 Auditing Practices Group states that the process approach incorporates the Plan-Do-Check-Act (PDCA) cycle and risk-based thinking. In practice, that means every documented process should have its own small PDCA loop: an owner, a target, records, a periodic review, and a way to act on the results.

PDCA Worksheet: A Worked Example

Use the worksheet below to run one PDCA cycle on a single process. The example column is hypothetical: a small distributor whose customers complain about late shipments. Replace it with your own process, target, and records.

Keep each cycle small enough to finish. One process, one target, and one change at a time make the “Check” step meaningful, because you can connect the result to what you changed.

Plan Do Check Act (PDCA)

So there you have it. Plan-Do-Check-Act, or PDCA, for short. It’s one of the cornerstones of the quality world and the ISO 9001 standard. If executed correctly, it can help you get control over a seemingly chaotic world. Yes, it is hard to do PDCA right…but what’s worth doing well that isn’t difficult, too?

If it were that easy, everyone would be doing it…don’t you think?

Frequently Asked Questions

What Is the Difference Between PDCA and PDSA?

They describe the same four-step loop. PDSA replaces Check with Study, which Deming preferred because the third step should explain why a result happened, not just confirm whether a target was hit.

How Does PDCA Relate to ISO 9001?

ISO 9001 uses the process approach, which incorporates the PDCA cycle and risk-based thinking. Each process in a quality management system should be planned, carried out, measured against its objectives, and improved.

How Long Should One PDCA Cycle Take?

Long enough to collect enough data points to see a real trend. For a weekly measure, that often means about a quarter. Small, frequent cycles on one process usually teach more than one large annual review.

Is Corrective Action the Same as the Act Step?

Corrective action is one way to act, used when a problem or nonconformance needs its cause removed. The Act step also includes standardizing changes that worked, making improvements, managing change, and sending feedback.