First, the standards have to be specific enough to be useful guides, yet general enough to allow for some flexibility. In repetitive manual work, standards are pretty specific. In engineering, since there are no fixed quantities, the standards need to be more variable. For example, knowing how the curvature of the hood of a car will relate to the air/wind resistance of that body part is more useful than knowing a specific parameter for the curve of the hood.
Second, the people doing the work have to improve the standards. There is simply not enough time in a workweek for industrial engineers to be everywhere writing and rewriting standards. Nobody likes following someone’s detailed rules and procedures when they are imposed on them. Imposed rules that are strictly policed become coercive and a source of friction and resistance between management and workers. However, people happily focused on doing a good job appreciate getting tips and best practices, particularly if they have some flexibility in adding their own ideas. In addition, it is very empowering to find that everyone is going to use your improvement as a new standard. Using standardization at Toyota is the foundation for continuous improvement, innovation, and employee growth.