Case Study

The average number of strokes for a tool is 45,000.

The standard deviation is 2,500 strokes.

A punch has a total of 25 mm that can be ground off before it is no longer useful.

Each regrind to sharpen a punch removes 1 mm of punch life.

The cost to regrind is:

2 hours of press downtime to remove and reinsert tool, at $300 per hour

5 hours of tool maintenance time, at $65 per hour

5 hours of downtime while press is not being used, at $300 per hour

The average wait time for unplanned tool regrind is 15 hours at $300 per hour.

Because of the large number of strokes per tool regrind, this is considered to be a continuous distribution. The normal curve probability distribution is applicable.

Case Study Part II

Given your analysis of Part I of the case study, what is the probability that:

1)The tool will be pulled for regrind 20 times

2)The tool will be pulled for regrind 23 times

3)The tool will be pulled for regrind 18 times

4)The tool will be pulled for regrind 25 times