Page 294 - (DK) The Business Book

292 LEAN PRODUCTION

looking for tools, walking from one The final muda is the production
part of the factory to another, or of defective items. Substandard
bending to pick up parts. This type products signify waste of time and
of waste increases cycle time—the resources, and mean that further
time taken to produce a unit of inspection processes are required
output. Longer cycle times lead to and the products must be reworked.
lower productivity, which in turn In addition to the seven types of
drives up unit labor costs. muda, Toyota identifies two other
The fourth muda is time spent potential problems: mura and muri.
waiting. Delays may occur when Mura is uneven flow in a process,
machines on a production line are leading to unbalanced working
poorly coordinated, resulting in practices. Muri is the overburdening
bottlenecks. Time might also be of people or equipment.
wasted resetting machinery to
Holding goods in stock is a cost for produce a different part. Lean strategy
a company, since warehouse space
and employees need to be paid for. In The fifth muda is transportation. Using these insights, production
addition, cash tied up in stock could be Time and money spent moving engineer Taiichi Ohno developed
in the bank instead, earning interest. work-in-progress from one factory the Toyota Production System
to another will drive up costs, and (TPS). This lean production method
materials and work-in-progress is this is unlikely to add value to the counters waste in the production
considered wasteful because of the product, so it is wasteful. process by producing more using
associated space and staff costs. The sixth example of muda is less. It enables a manufacturer to
The third type of muda that overprocessing. Consumers will increase output without having to
Shingo identified is movement. In only pay for the product features pay for extra labor, raw materials, or
some factories, workstations are that they value. Producing complex, capital. Alternatively, a business
badly designed, and employees overengineered products is wasteful can use lean production techniques
spend time doing things that do not because it creates additional costs to make a better-quality product
add value to the product, such as without any extra revenue. that will sell for a higher price.

Muri, mura, and muda are three
Japanese terms identified by the
Toyota Production System as MURI
problems to avoid. Muri refers Overburdened
to the overburdening of
individuals or teams, which JUST-IN-TIME
is inefficient; mura means
an unbalanced work flow,
which can cause
bottlenecks in supply;
and muda are all the
areas of waste
in a system.
MURA MUDA
Unbalanced Waste

A just-in-time supply system
eliminates muri, mura, and muda
from the production system, so that
teams receive materials as they
need them and waste is avoided.