*Concepts, Applications and Emerging Opportunities in Industrial Engineering*


Lean principles suggest a stronger connection to the physical part of the Toyota approach than to its human side. The term "Lean", in my interpretation, may have been the term chosen by the perception that the researchers had to what they observed in Toyota factories. The reduction of waste ("fat"), especially the reduction of WIP (and the consequent increase in the flow of articles throughout the manufacturing processes) would be easy to observe. This fact may have given the idea of "leanness" as can be interpreted when looking at **Figure 2**.

As it can be seen at the bottom part of **Figure 2**, a smaller amount of WIP is metaphorically represented by a narrower pipe, i.e., it can be said that the production looks "leaner".

Different scholars of Toyota's approach vary greatly in the emphasis they give to the technical aspects and human/culture aspects. If we look at the five Lean principles, we realize that 4 of them are dedicated to technical aspects while only one is dedicated to a mixture of technical aspects and human/culture aspects. It is the principle of continuous improvement or pursuit perfection which is in fact the central theme here in the chapter.
