Page 38 - How To Implement Lean Manufacturing

Lean Manufacturing and the Toyota Pr oduction System 19

people misunderstand the word “integrity” and misuse it. This is not all that uncommon.
Words will often change meaning due to misuse. Integrity, integration, and the word
integer all have the common root in the Latin word, integrare, which means to make
whole. The word integrity means “state or quality of being complete; undivided; unbroken,”
(from my Webster’s New Collegiate Dictionary). The TPS is a highly integrated manufac-
turing system, and is distinct from most manufacturing systems. It is integrated internally
as well as externally; horizontally as well as vertically.
How is it internally integrated? What are the characteristics it has that lead us to call
it integrated? First, it operates as one system from beginning to end, which is the supply
to the customer. It is a whole system, with the customer being the pacesetter of the
process by consuming the product. A series of pull signals, starting with customer con-
sumption, cause the system to operate in unison: a take-one-make-one system. Every
technology is challenged to make the system “flow.” Every technology is challenged to
speed up the flow of the product through the system. Every technology is challenged to
reduce the distance the product travels and the time it takes to deliver the product to the
customer. Every effort is made to shrink the system in both time and space; this makes
it more compact and smaller. The opposite of an integrated system would be a dis-
integrated system. A system that is scattered and a series of islands connected in some
fashion. The TPS is designed to eliminate these islands of production whether they are
batches or large “monument” machines requiring very long setup times.
Second, and most importantly, the TPS is integrated because there is a deep under-
standing of the concept of systems and that the system is the entity that requires optimi-
zation. They fully understand that “the system optimum is not necessarily the sum of
the local optima.”
Most manufacturing systems strive for local optimum conditions that are often at
odds with the overall optimum. For example, they will strive to have high machine or
manpower efficiencies, even if that means overproduction and finished goods sitting in
the warehouse without sales to pay for them. The goals system and the accounting sys-
tem in most plants are geared to drive toward these local optima. If managers proceed
without an understanding of the local impacts on the system performance—that is,
proceeding without an understanding of the integrity of the system—it is easy to push
the entire system to a nonoptimum location: or simply put, to waste money. When a
manager is striving to optimize the performance of his division amid the changing
demands of the customer—a process that includes delivery, personnel, and raw materi-
als problems—it is often difficult, if not impossible, to maintain focus on what is best for
the system.
So internally the TPS is integrated as it operates as one entity—in a synchronous
fashion—and always strives to optimize the system to supply maximum value to the
customer.
However, the TPS was the first system to become externally integrated as well. It is
externally connected to both the customer and the supply chain. It is connected to the
customer because the customer wants value and that is the foundation upon which the
TPS is built. Most production systems are built on the concept of providing volume at
low cost, which does not connect them as directly to the customer.
The TPS is connected to the supplier chain as if the supply chain was an extension
of the plant itself. Ohno started incorporating what he calls the “cooperating firms” in
TPS concepts before the oil crisis of 1973. In his book, The Toyota Production System,
Beyond Large Scale Production, (Productivity Press, 1988) he stated: