Understanding Lean Manufacturing

Lean manufacturing, lean enterprise or lean production is a production practice that considers the expenditure of resources for any goal other than the creation of value for the end customer to be wasteful, and thus a target for elimination. And essentially, lean is centered on preserving value with less work.And it is a philosophy derived from Toyota Production System known as TPS.[1]

However, when talking about the implementation of lean manufacturing technology, the discussion arise about whether all the rules or some part of the rules make sense when applying to specific industry.

For example, when we are thinking about lean manufacturing, it means to create urgency, stress and discomfort. However, the normal human reaction is more inclined to comfort and less stressful.

So does it mean is there something wrong here?

There is one example[2]: One engineer stated that he decreased the machine downtime. At first, it sounds like a very exciting news since the stability of the machine has improved. However, when interviewing the engineer about the process of correcting the problem, he indicated a very common misconception of lean manufacturing. He replied that he had installed a large in-process buffer after the troublesome machine so that the NEXT process would not incur any downtime.[2]

In this case, there are two misunderstandings. 

First, by adding additional buffer, it increases cost and inventory.There could be potential risks associated with the additional buffer.

Second, by doing so, it shows weakness to the customer. At Toyota buffers and excess inventory are seen as indicators of weakness in the system. Challenges to reduce or eliminate inventory are issued and diligent efforts are made to strengthen the system and improve reliability.[2]

The core value of lean manufacturing is to strengthen the whole system. If applied properly the lean methods will make any shortcomings in the system appear quickly, and the shortcomings will have profound impacts. 

Indications of the success of a lean implementation are[2]:

• Problems will surface quickly and obviously (at times painfully).
• A sense of urgency will automatically be created regarding system reliability.
• The weakest point of the system will be stressed and broken.
• Operations will be forced to be close to the edge and as tight as possible.
• Consistent application in all areas and in the thinking and development of our practices[2].

Citation: 

[1] Wikipedia definition of Lean Manufacturing: http://en.wikipedia.org/wiki/Lean_manufacturing

[2] The reality of Lean Manufacturing: http://www.sae.org/manufacturing/lean/column/leanmar01.htm

[3] Lean Manufacturing Consultants: http://www.austop.com/Lean_Manufacturing_Consultants.php