Toyota Way Fieldbook : A Practical Guide for Implementing Toyota's 4Ps

Therefore: The line stops.
The robot breaks down. Start with the perceived problem and work up to
find the true problem.
Once the true problem and resulting symptoms are identified, it’s possible
to compare the full implications of the true problem and consider the value of
proceeding with the process of solving the problem. It is still necessary to define
the extent of the problem and its characteristics.

Defining the Problem

In order to be defined as a “problem,” four pieces of information are required:

1. The actual current performance with some historical trend detail.


2. The desired performance (standard or goal).


3. The magnitude of the problem as seen by the difference between the actual
   and desired (sometimes referred to as the “gap”).


4. The extent and characteristics of the problem or situation.
   When presenting this information, a picture is worth a thousand words.
   Always try to explain the situation visually with a trend graph (Figure 14-5). The
   trend graph should include enough historical data to show how long the condi-
   tion has existed (for long-term performance improvement opportunities a mini-
   mum of six months is recommended if available). The data should be displayed
   so the characteristics of the problem are seen. For example, does the problem
   appear to be getting better, worse, or staying the same? This understanding assists
   in determining the importance of addressing this problem versus other prob-
   lems. If the problem is getting worse, more immediate action may be necessary,
   such as a short-term countermeasure. If the situation is getting better or staying

334 THETOYOTAWAYFIELDBOOK

Monthly Units per Hour

Fabrication Line

0

10

20

30

40

JanFebMarAprMayJunJulAugSepOctNovDec

Units per Hour

Goal = 36

Figure 14-5. Trend chart of monthly units per hour