The Principle: Standardization Is the Basis for Continuous Improvement and Quality
Toyota’s standards have a much broader role than making shop floor workers’ tasks repeatable and efficient. The Toyota Way results in standardized tasks throughout the company’s white-collar work processes, such as engineering. Everyone in the company is aware of and practices standardization. For example, an engineer can walk into any Toyota factory in the world and see almost identical processes. Toyota also applies standards to the design of products and manufacturing equipment.
Managers have a misconception that standardization is all about finding the scientifically one best way to do a task and freezing it. As Imai (1986) explained so well in Kaizen, his famous book on continuous improvement, it is impossible to improve any process until it is standardized. If the process is shifting from here to there, then any improvement will just be one more variation that is occasionally used and mostly ignored. One must standardize, and thus stabilize the process, before continuous improvements can be made. As an example, if you want to learn golf, the first thing an instructor will teach you is the basic golf swing. Then you need to practice, practice, and practice to stabilize your swing. Until you have the fundamental skills needed to swing the club consistently, there is no hope of improving your golf game.
Standardized work is also a key facilitator of building in quality. Talk with any well-trained group leader at Toyota and ask how he or she can ensure zero defects. The answer is always “Through standardized work.” Whenever a defect is discovered, the first question asked is “Was standardized work followed?” As part of the problem-solving process, the leader will watch the worker and go through the standardized work sheet step by step to look for deviations. If the worker is following the standardized work and the defects still occur, then the standards need to be modified.
In fact, at Toyota the standard work is posted outward, away from the operator. The operator is trained using the standardized work, but then must do the job and not look up at the standardized work sheet. The standard work sheet is posted outward for the team leaders and group leaders to audit to see if it is being followed by the operator.
Any good quality manager at any company knows that you cannot guarantee quality without standard procedures for ensuring consistency in the process. Many quality departments make a good living turning out volumes of such procedures. Unfortunately, the role of the quality department is often to assign blame for failing to “follow the procedures” when there is a quality problem. The Toyota Way is to enable those doing the work to design and build in quality by writing the standardized task procedures themselves. Any quality procedures have to be simple and practical enough to be used every day by the people doing the work.