“The establishment of standardized processes and procedures is the greatest key to creating consistent performance. It is only when the process is stable that you can begin the creative progression of continuous improvement. As we’ve shown in the previous chapters, the work of developing standards begins early in a lean implementation and is a common thread throughout the development of lean operations.” 

The Toyota Way Fieldbook by Jeffrey Liker & David Meier (McGraw-Hill, 2006) pp. 111-112.