Page 371 - The Toyota Way Fieldbook

Chapter 15. Complete a Thorough Root Cause Analysis 345

therefore, they have a “high tendency” of occurrence. The cumulative effect of
these small losses can be very great. In addition, the reduction will generate an
immediate and continuous payback. A small payback that can be captured
immediately and will continue to pay forever is a preferred result. Small cycle
time losses are also generally easy to correct. They may include excessive oper-
ator or machine motion, delays due to waiting, or overprocessing (doing more
than necessary). Of course, these are all forms of muda (waste), and the removal
of muda is a primary objective.
Visiting the workplace, you will probably see many other examples of cycle
losses and process stoppages. You’ll need to gather facts to understand the total
impact of each issue—the importance, urgency, and tendency—and a simple way
1
to do this is to use a value-added/non-value-added breakdown list as shown in
Figure 15-3. The example is from a sawing operation, but the list generated is fair-
ly typical in most manufacturing operations. Remember, the links of the causal
chain were related to losses of time, either through cycle losses or due to losses of
time when the operation is not running or not adding value. The list that is gener-
ated will include both cycle and run-time losses. Since the ultimate objective is to
find causes that are linked through the causal chain to the original problem, we’re
looking only for those activities that take time away from the value-adding task.
In other words, if the operator is performing a non-value-adding task but the
machine is adding value while the operator does the task, improving this item will
not lead to reducing the problem, and thus is not a beneficial improvement. The
first priority is to address the issues that directly reduce the time available to add
value and therefore cause a loss of production.

Value-Added Task Non-Value-Added Task
Load saw
Blade is cutting wood Unload saw
Change blade ALL ACTIVITY
Clean up OTHER THAN
CUTTING WOOD IS
Break down
Inspect parts NON-VALUE-
Move finished parts ADDED ACTIVITY
Meetings
Waiting for wood
Handling wood

Figure 15-3. Value-added/Non-value-added analysis

For further information on the case see: Bill Costantino, "Cedar Works: Making the Transition to
Lean," in J.K. Liker (ed.), Becoming Lean, Productivity Press, 1997.