Page 31 - How To Implement Lean Manufacturing

12 Cha pte r T w o

process) andons (visual displays such as lights to indicate process status especially
process abnormalities), and 100 percent inspection by machines. It is the concept
that no bad parts are allowed to progress down the production line. This not only
is needed to protect the customer and reduce
scrap costs, it is a continuous improvement tool
Point of Clarity The TPS is and is a key element in making kanban work. It is
a quantity control system. a violation of kanban rules to allow bad parts to be
transported.

What Is Really Different about the TPS?

Technical Issues
So just what is different about the TPS? What makes it so revolutionary? The answer to that
is not so simple. First, let’s look at the technical aspects, particularly some of the industrial
engineering aspects. These technical skills and tactics are the foundation for the quality and
quantity control aspects (items 1 and 2 from our Five-Fold Definition of the TPS). Some very
old engineering techniques are used within the TPS. In addition, some old techniques with
new twists, as well as some totally new techniques, are also included. Later, we will address
the deeper issues of the integration (item 3), the evolution of the system (item 4), and the
cultural differences (item 5). But as I said, let’s first discuss some of these technical issues.
We will compare several aspects of a manufacturing system as either Normal Mass
Production Model (MassProd) or as Lean. And where the TPS stands out among Lean
facilities, we will highlight that as well. These manufacturing aspects include:
• The makeup of the typical production cell/line and how quality is handled
• Handling multiple models of a product
• The use of “pull” versus “push” technology
• The issue of changeover times
• How parts and subassemblies are transported in the plant
• How finished product demand and supply variations are handled
• How quality is managed
• How cycle time variations are managed
• How line availability is managed

In the next subsection, we shall review them in order.

The Typical MassProd Production Cell/Line
The makeup of the typical MassProd production cell/line is normally a flow line. The
typical flow line has work stations lined up in a row. It has inventory in front of and
after each station. These work stations operate more like production islands rather than
a connected process. The production of each station is maximized to improve equip-
ment utilization, they call this “optimization” and product is pushed to the next station.
This station-by-station “optimization” and “push production” are extremely key issues.
The production rate is determined by the plan and all too frequently each island has its
own plan. Normally product is produced, one model at a time, in large batches. There