
186 ◾ New JIT, New Management Technology Principle
accumulated failure rate of 70% is the life span of the defective parts in the initial
failure form. e results mentioned above are shown in Figure 7.29a.
Next, to nd the proper heating and holding time, the author made an Arrhenius
plot (Shiomi, 1970) of life span against temperature change. e results, shown in
Figure 7.29b, reveal the life span. is allows us to determine the tolerance time
(L
1
) in the acceleration test for temperature T
1
, which is determined by the heating
equipment.
7.4.3.1.2 Random Failure
7.4.3.1.2.1 Reliability Design for the Robot Line — In the random failure
mode, ...