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 realises 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 summarised, but also analysed: 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 analysed and it is recognised 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 minimised. 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.