KAIZEN: continuous improvement

• Kaizen: the basis of TPS (Toyota Production System)
• Kaizen Kaikaku and Kakushin
• The PDCA Cycle

Kaizen: the basis of TPS (Toyota Production System)

At the basis of the TPS (Toyota Production System) there is the Kaizen philosophy.
The Japanese term Kaizen is a combination of two words: KAI which means change, and ZEN which means better: hence the meaning of continuous improvement.
This is a fundamental concept in Japanese culture, and one that we also find in TPS.

Working according to the Kaizen philosophy means always striving for continuous improvement, based on the assumption that everything we do can be improved. Even when we think we have achieved perfection, this is not actually the case, as everything can and must be improved; the perfection achieved becomes nothing more than a standard, which can be improved upon. All the concepts found in the Kaizen philosophy are then obviously incorporated into the Lean Production system.

Another fundamental concept of Kaizen is that energy comes from below: analysing Lean Production, we see that decisions or suggestions must come from below and must not be imposed from above, as happens in other production models. This is also why, in order to apply Lean Production, it is necessary to involve all levels of the hierarchy, even the lowest ones. Furthermore, Kaizen, like Lean Production, is based on small but continuous changes.

The concept of not letting a day go by without making some improvement, however small, is typical of Japanese culture, unlike what is applied in Western industry. In the West, companies tend to keep their structure and form unchanged for many years, and the only visible changes involve technological innovations requiring high investment.

KAI (change) – ZEN (better)

” A proper standard procedure cannot simply be described from behind a desk. It must be tested and reviewed many times in the production plant. Furthermore, it must be a procedure that everyone can recognise and understand at a glance. In order for production workers to be able to draw up a standard worksheet that others can understand, they must be convinced of the importance of what they are doing.“(Ōno, 1978).

Kaizen, Kaikaku and Kakushin

The Japanese business management model sees improvement as consisting of two phases: Kaizen and innovation. Kaizen means improving through small but continuous efforts, while innovation means radical change through temporary but significant efforts.

The Kaizen (many small improvements), whose main feature is continuity, contrasts with Kakushin (innovation) and to Kaikaku (a significant improvement).
While Kakushin and Kaikaku are decided by management and require large investments, Kaizen is carried out every day by all staff.

The difference between Kaizen and innovation can be imagined as the difference between a staircase and a climb. Innovation leads to a sudden improvement in standards. This sudden improvement remains unchanged until the introduction of a new innovation and therefore has a similar trend to many climbs, while Kaizen, with its small but continuous improvements in standards, has a step-by-step trend. It would be wrong to think that Kakushin and Kaizen are mutually exclusive. On the contrary, the best management system is one that provides for the coexistence and use of both systems in the company: innovation, to define the new revolutionary standard, and Kaizen, to ensure that innovations are not eroded over time, but rather continuously perfected.

The PDCA cycle

A key element in implementing the Kaizen philosophy is the PDCA cycle (or Deming Cycle). This cycle represents a cyclical methodological approach that promotes continuous excellence through four interconnected phases: Plan, Do, Check and Act.

PLAN

In this phase, objectives are defined and the actions necessary to achieve them are planned. It is in this first phase that the strategies and tactics to be adopted are outlined, together with an in-depth analysis of potential improvements.

DO

In this second phase, the planned actions are implemented. This is when the ideas come to life and the planned changes are introduced into the process.

CHECK

This phase is dedicated to evaluating the results obtained against the set objectives. Various performance indicators are taken into consideration to understand whether the changes made have led to the desired improvements.

ACT

Finally, in this last phase, based on the previously verified results, any corrective actions are implemented and then the process restarts. This phase is essential for consolidating successes, learning from challenges and continuing the path of continuous improvement.