Facility Maintenance

Typical Job Categories for Maintenance Plant Maintenance General Mechanics Machinists Sheet Metal Workers Welders Electronics Technicians Computer Technicians Typical Job Categories for Maintenance Plant Maintenance Electricians Tinsmiths Welders Pipe fitters Fire/emergency People Steam fitters Bricklayers Painters Glaziers Concrete Workers Carpenters Millwrights Heavy Movers Window Washers Janitors Gardeners Machine Maintenance General Mechanics Machinists Sheet Metal Workers Welders Electronic Technician Computer Technicians

MAINTENANCE PROCEDURES  Emergency Maintenance  Preventative Maintenance

Cost to Rent Number of Machines Out of Order Probability that Number of Machines will be broken: Total =100% Emergency – Standby Capacity

We have a line with 50 robot GMA welders  The cost to do a preventative maintenance overhaul on each machine is $200/machine  Average breakdown repair costs are $700/machine Objective: Calculate the cost if we elect to repair only when a machine breaks down. How much must we set aside each month?

Probability of Breakdown as a function of months after overhaul of all machines The months time the probability results in the partial expected time for failure. Since the partial probabilities add to 100%, the partial times add to the expect time for a failure = 8.42 months They Add to 100%

The cost of repair-on-breakdown then = ($700/machine) /(8.42 months) * 50 machines = $4157/month Thus, we better place $4157 in a fund every month if we decide to do repair-on- breakdown policy.

We have a line with 50 robot GMA welders  The cost to do a preventative maintenance overhaul on each machine is $200/machine  Average breakdown repair costs are $700/machine Objective: Calculate if preventative maintenance should be done and if so what the schedule should be.

Calculate Cost for Preventative Maintenance For every preventative maintenance overhaul we do it will cost: = $200/machine * 50 machines = $10,000 If we do a preventative maintenance every month, it will cost $10,000/month If we do a preventative maintenance every 2 months, it will cost $5,000/month, etc.

Even though we do preventative maintenance, we can expect some breakdowns to occur anyway. We can calculate the number of expected breakdowns each month using the following equation. Where: B n = expected number of breakdowns N = number of machines P n = probability of machine breakdown in period n  That is, 2.5 breakdowns in the first month  That is, 3.63 breakdown in first 2 months

Expected Cost = Ave. Number * $700/machine = 2.5 * $700 = $1750 Total Cost = Expected Cost + Prev. Maint. Cost = = PLOT

$4157