There are various non-statistical tools that have been typically developed by lean companies, notably by Toyota for minimizing variability in production, such as standardization, introduction of takt time, synchronization, shortening the total production lead time which I am fond of referring to as non statistical tools.

I have a theory that among the large Western companies (mostly American) the higher an executive is promoted, the more wisdom is lost and by the time he or she reaches the top becomes a complete idiot. Certainly they do not deserve the outrageous salary.

Control charts are one of the statistical tools for solving quality related problems.

Under the lean system, any tools which are required for solving problems are used.

You can't do kaizen just once or twice and expect immediate results. You have to be in it for the long haul.

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 improvement can be made.

Where there is no standard, there can be no improvement. For these reasons, standards are the basis for both maintenance and improvement