Kaizen is a Japanese word that stands for “improving” or “making better” and refers to any kind of improvement no matter how insignificant it may seem: it concerns one-time and continuous changes, small- and large-scale ones. The approach was chosen as it simultaneously improves all aspects of the production (including supply chain management) and involves all people working for the company from assembly line workers to the CEO. The approach is universal and can be successfully used in a number of different fields (automobile industry, health care, banking, etc.). In Japanese, Kaizen mostly refers to industrial and business organizations (as it was first practiced by Japanese businesses in the post-war period and later heavily promoted by Toyota), whereas in English, the word is not associated with any particular sphere but usually signifies continuous improvement.
There are two major types of Kaizen that differ mainly in the scope of their implementation: flow Kaizen is meant to transform the flow of data and materials, which presupposes the entire restructuring of the manufacturing process while process Kaizen implies the improvement of individual workplaces as well as the ways workers perform their jobs. In the given case, the company opted for a combination of both processes, though the emphasis was made on the first type.
The success of the model is explained by the fact that it teaches workers to look for small ideas for change that can be tested immediately, which is quite different from classical improvement models that presuppose huge time gaps between the appearance of a concept and its practical application. Kaizen is aimed to eliminate excessive amount of work and teach people how to do the same job using less time and effort. People are encouraged to use experimental methods in their workplace and thereby reduce waste. This allows claiming that Kaizen is not a well-defined plan or strategy but rather an approach or philosophy of doing things.
Implementation of such a human-oriented method leads to increased productivity since it encourages participation in quality improvement processes and creates a feeling of belonging. The approach gives workers maximum freedom in developing and expressing their creativity as it can be used individually or in a group of any size (which also improves teamwork). If Kaizen is applied on the largest possible scale (to improve the work of all departments), it becomes the basis for total quality management (which is the case with the company used in the project).
There are five basic elements of Kaizen:
- teamwork and cooperation;
- individual discipline of employees;
- high morality;
- quality circles;
- change suggestions.
In order to understand Kaizen, it is important to know related concepts:
- Productivity is understood as the ratio between output (the amount of quality goods produced) and input (the amount of resources that were required for the production including machines, tools, labor, and materials).
- Cycle time is a period of time needed to complete a certain number of tasks that comprise one cycle.
- Takt time is a period of time that is supposed to be sufficient for manufacturing a product that the client orders (is usually calculated by ratio of net available time by the demand). It is highly important for Kaizen to reduce takt time as it allows meeting the customer’s requirements.
- Muda is a term applied to any process that increases the cost of the production but does not add any value, which leads to the waste of resources. There are seven kinds of muda: 1) muda of over-production; 2) muda of waiting or non-productive time; 3) muda of transportation or logistics; 4) muda of processing; 5) muda of equipment; 6) muda of motion; 7) muda of defective parts and reworking.
- Muri is a term used to signify excessively hard work and the strain that may have a negative impact on productivity.
The cycle of Kaizen consists of four activities referred to as PDCA cycle:
- Plan: define goals and processes that are to be performed in order to obtain the required output. Future improvement largely depends on the accuracy of planning.
- Do: introduce the improvement developed at the initial stage after preliminary testing (on a smaller, experimental scale).
- Check: study the results of the experiment to see if they correspond to the required outcome. If they fail to meet expectations, changes must be introduced in order to enable effective execution of the innovation.
- Act: if it was proven at the previous stage that the change is a real improvement, it automatically becomes a new standard for action. In case the result turns out to be worse than before the change was introduced, the current standard will remain as it is. There is also a possibility that the result will be different from the expected but not negative. This means that additional testing is required.
Kaizen also implements 5 Whys interrogative technique in order to identify the root cause of the issue and successfully eliminate it together with the negative effects produced. The technique is based on the ongoing repetition of the question “Why?” until all the answers are found and the problem is understood completely. Each question provokes the next one up to the point at which the information is sufficient to find a solution. However, the company should be ready that not all the problems have only one underlying root cause, which means that several series of questions may be required to find out multiple causes. In order to implement this Kaizen technique successfully, an organization must follow some guidelines:
- all the parties involved should be a part of the 5 Whys process, which would allow conducting a thorough investigation of the issue;
- it is better to organize a meeting and use whiteboard to give the problem under discussion a visual representation;
- after the problem is written down, it must be ensured that all people understand its essence;
- causes and symptoms should not be mixed up;
- it is important to preserve the logical sequence of questions without omitting even those than seem too obvious;
- if there are multiple root causes, all of them should be identified before Kaizen is implemented;
- questions should be answered accurately and precisely, avoiding any kinds of digressions;
- conclusions must not be pre-mature even if they seem evident;
- all answers should be based on objective data without any personal opinion on the topic;
- the process should be freed from any kind of bias: it is crucial to assess ideas suggested by people but not their personalities;
- The ultimate response to 5 Whys should not be formulated in the form of an accusation: no one should be blamed for the problem since such an approach to solving it is not productive;
- the answer to the questions should presuppose that the problem will never occur again;
- all the questions and answers must take the customer’s perspective as the principal one.