The PDCA cycle: more success with the Deming cycle

Whether you’re an employer, employee, or self-employed, everyone wants to do their job as ef­fi­cient­ly as possible. Increased pro­duc­tiv­i­ty not only leads to better results, but can also improve personal sat­is­fac­tion. In­creas­ing pro­duc­tiv­i­ty is a con­tin­u­ous process. You can keep on working to improve processes: it can be an ever­last­ing cycle if you get involved.

The physicist Walter Andrew Shewhart already had this insight in the 1930s. He developed a cyclic method for quality assurance. His student William Edwards Deming refined the theory, which is why we often speak of the Deming cycle today. Others are most familiar with the term PDCA: the sequence of plan, do, check, and act.

The over­rid­ing goal is to learn con­tin­u­ous­ly. This is why the PDCA cycle is so versatile: Man­age­ment can benefit from the circular model, making work processes in pro­duc­tion or in everyday office life more efficient. But the life of each in­di­vid­ual can also benefit from the ap­pli­ca­tion of PDCA.

The PDCA cycle was designed with the aim of es­tab­lish­ing a con­tin­u­ous model for the con­tin­u­ous im­prove­ment of processes: quality assurance that is efficient and con­tin­u­ous. However, the model can be applied in many contexts, es­pe­cial­ly through the ex­ten­sions of Deming. Behind PDCA is a model that is useful for any learning process and im­prove­ment.

To do this, you follow the four steps plan, do, check, act. This can be applied not just to work processes, but also to the resulting products and services, as well as to the people them­selves. PDCA therefore helps, for example, to improve teamwork like the stability of a sales item.

The PDCA cycle is a popular tool for im­ple­ment­ing a con­tin­u­ous im­prove­ment process (CIP). This way of thinking is based on the as­sump­tion that a company must continue to improve in order to compete in the market. The Deming cycle serves as a concrete plan for im­ple­ment­ing the idea of CIP.

The model is divided into four phases that form a circular, repet­i­tive process.

You start with a planning phase: What problems have you iden­ti­fied and how can you best address them? To do this, you first determine the current situation. The problem is then outlined so that you can determine exactly how the goal should be achieved. This also includes the concrete planning of the required resources. Here, too, you first determine the current state and then scale to what is ad­di­tion­al­ly required.

After all, the team also has to agree on success factors. What must happen for the changes to be con­sid­ered suc­cess­ful­ly completed? Only when you have defined the goals con­crete­ly can you also measure whether you have achieved an ac­cept­able result. This also includes choosing goals that are re­al­is­ti­cal­ly achiev­able. There is no point in defining utopian successes that cannot be achieved within a rea­son­able timeframe and with jus­ti­fi­able effort anyway.

After planning, the im­ple­men­ta­tion phase begins. The team or the in­di­vid­ual now realizes what they planned in the first phase. It is best to proceed in small steps and question the im­ple­men­ta­tion again and again. In this way, you can ensure that you do not lose control during im­ple­men­ta­tion and stick to the plan. In practice, it has also proven suc­cess­ful to test the change process only on a small scale – e.g. first on a product, not on the complete product range, or only in one de­part­ment and not in the entire company.

Therefore, this second step can also be regarded as a test phase. You use this time to gather knowledge: Just because you’ve planned something through properly doesn’t mean it will work in practice. The ex­pe­ri­ences you gain in the do phase directly initiate the third phase.

During the review, the collected results are compared with the ob­jec­tives set. You look crit­i­cal­ly at what worked and what went dif­fer­ent­ly than expected. It is important to look ob­jec­tive­ly at the plan and its im­ple­men­ta­tion. It doesn’t help the im­prove­ment process to gloss over results in order not to endanger your own strategy. Problems in the do phase are not to be seen as setbacks, but as op­por­tu­ni­ties to learn from them – because that is what this phase is meant for.

In the check phase, the results are not only sum­ma­rized, but also analyzed: Why didn’t every­thing go according to plan? Once you have found out how the problems came about, you can change the plan ac­cord­ing­ly and achieve better results next time.

Now that the problems are known and the causes have been iden­ti­fied, the plan can be adapted and finally im­ple­ment­ed. While the do phase was a test run and carried out on a small scale, the fourth step comprises the overall picture. Depending on the framework in which you use the PDCA cycle, you extend the ap­pli­ca­tion.

Once the trans­for­ma­tion is completed, the new state is con­sid­ered standard. You should not let the quality standard de­te­ri­o­rate. Therefore, you need to install a form of control. You can always question yourself and make sure that you don’t fall back into old patterns; someone else – a mentor, a su­per­vi­sor etc. – can also take over this control function. It is important for the further de­vel­op­ment that you don’t step back again. PDCA begins again in the new state.

Let’s take a furniture factory as an example. The man­age­ment wants to increase the output of cabinets. They notice that most of the cupboard is finished quickly, but they regularly wait for their round feet. At this point, a PDCA cycle should help.

During the planning phase (plan), you notice that the lathe used to produce round objects is prone to errors. Often the excess has to be disposed of, which not only slows down the pro­duc­tion chain, but also leads to un­nec­es­sary ad­di­tion­al ex­pen­di­ture. So they are planning to buy a more modern machine. Instead of directly replacing all the relevant machines, you start with just one to test the success.

In the second step (do), the new machine is tested in practice. The work completed with the new machine is checked for one month. At the same time, however, the older machines continue to run. This gives those re­spon­si­ble the advantage that they can now see exactly whether the in­vest­ment in the new machine is worth­while.

One notices that although the pro­duc­tion error has been contained, the pro­duc­tion speed has hardly increased at all. In the third phase (check), this problem is analyzed and it is rec­og­nized that the employees are so used to the old machine that they still have dif­fi­cul­ties using the new one just as ef­fi­cient­ly.

Therefore, the plan will now be amended and then fully im­ple­ment­ed in the final phase (act): All machines are now replaced and at the same time, the employees receive detailed in­struc­tion on the new equipment. As a result, pro­duc­tion of the cabinets is sig­nif­i­cant­ly ac­cel­er­at­ed and scrap is minimized. The company now accepts the new pro­duc­tion speed as standard.

PDCA is a wonderful tool for in­tro­duc­ing im­prove­ments in a sus­tain­able and thought­ful way. Instead of changing the usual pro­ce­dures with a spon­ta­neous hair-jerk procedure, one proceeds with small steps and always under close ob­ser­va­tions. However, this is also one of the big dis­ad­van­tages of the Deming cycle: You have to plan enough time for the model. PDCA does not allow for rapid problem solving.