Volume 1 , Issue 1 Page 38
The lean in lean manufacturing refers to the elimination of all waste . Waste is defined as any activity that creates no value-and value is defined by the end user / customer . Before we can even talk about waste , we need to define what is value added versus non-value added processes in a manufacturing environment . Value added is any activity that changes the fit , form , or function of a product . This typically is a modification to a products / services performance that enhances its efficiency . The key to value added is that the customer must be willing to pay for these activities .
So , what is non-value added ? Non-value added is any activity that does not change the fit , form , or function . The customer is typically not willing to pay for these . These are the costs that must become the focus to be reduced or eliminated .
Lean manufacturing derives much of its direction from the methods used by the Japanese automobile manufacturer Toyota . These methods became internationally recognized as a result of Womack , Jones , and Roo ’ s book , The Machine That Changed the World ( 1990 ). They studied the practices of 90 automobile assembly plants in 17 countries to learn about Japanese successes in manufacturing . They reported that the hallmarks of lean production are teamwork , communication , and efficient use of resources . The lean approach for manufacturers is to improve their organizations by focusing on the elimination of any and all muda — the Japanese word for waste . The approach focuses on continuous system wide improvement , not only in the manufacturing division but business wide , and advocates methods to control the flow of material on the shop floor ( Moore and Scheinkopf , 1998 ).
A few years before The Machine That Changed the World was published , Taiichi Ohno , considered by many to be the father of lean manufacturing , published his book , Toyota Production System ( 1988 ).
Ohno explained the main foundations of lean manufacturing . These principles guided the Japanese companies that were described as “ world class ” by Womack and Jones ( 1996 ). Ohno identified eight categories of muda which cover virtually all of the means by which organizations waste or lose money . As described by Ohno ( 1988 ), the eight wastes are as follows ;
1 ) Defects
Defects are usually due to inspection and rework of defective material in inventory . Some causes of defects are :
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Weak process capability Poor quality controls Uncontrolled inventory levels Poor process documentation Misunderstood customer needs Design changes Poor machine capability
2 ) Overproduction
Overproduction is making more than is required by the customer , making earlier than is required by the customer and making product the customer does not want .