166 ◾ New JIT, New Management Technology Principle
1. In the initial period, the failure rate decreases (slope (m) < 1), in the middle
period it is constant (slope = 1), and in the latter period it increases (slope > 1),
indicating a bathtub-shaped failure rate. e failure rate in each of the three
sections can be modeled by a dierent Weibull distribution, so that the fail-
ures can be modeled by a sectional Weibull model.
2. e initial failures (where the failure rate decreases) occur up to a running
distance of 50,000 km. Failures in the intermediate range (where the failure
rate is constant) occur up to 120,000 km. Finally, failures occurring above
this value (where the failure rate increases) are due to wear.
3. e B10 mode life i