Management must provide employees with tools that will enable them to do their jobs better, and with encouragement to use these tools. In particular, they must collect data.

All models are approximations. Essentially, all models are wrong, but some are useful. However, the approximate nature of the model must always be borne in mind.

The management system which makes only a pretense of valuing employee involvement and encouraging employee empowerment merely breeds cynicism.

To find out what happens to a system when you interfere with it you have to interfere with it (not just passively observe it).

Just as the ability to devise simple but evocative models is the signature of the great scientist so overelaboration and overparameterization is often the mark of mediocrity.

All models are wrong, but some are useful.

The benefits provided by worker participation are twofold. Quality is improved because of the finding and fixing of a very large number of problems, but also, and perhaps equally important, moral is improved.