Question: Determine the optimum preventative maintenance frequency for each of the pieces of equipment if breakdown time is normally distributed.
Equipment Average Time (days) Standard Deviation between Breakdowns
A201 20 2
B400 30 3
C850 40 4
Equipment Preventative Maintenance Cost Breakdown Cost
A201 $300 $2300
B400 $200 $3500
C850 $530 $4800