Operations management by stevenson 9th ch15s

Learning Objectives Explain the importance of maintenance in production systems  Describe the range of maintenance activities key issues associated with it key issues associated with i

Maintenance

Learning Objectives

 Explain the importance of maintenance in production systems

 Describe the range of maintenance activities

key issues associated with it

key issues associated with it

to maintenance decisions

 Maintenance

 All activities that maintain facilities and equipment in good working order so

that a system can perform as intended

 Two basic categories

Goal of Maintenance

order at minimal cost

 To avoid production or service disruptions

 To not add production or service costs

 To maintain high quality

 To avoid missed delivery dates

Breakdown Consequences

may be injured

Reactive vs Proactive

Reactive Maintenance:

 Reactive approach; dealing with breakdowns or problems when they occur

Proactive Maintenance:

 Proactive approach; reducing breakdowns

through a program of lubrication, adjustment, cleaning, inspection, and replacement of worn parts

 Reasons for keeping equipment running

 Avoid production disruptions

 Not add to production costs

 Maintain high quality

 Avoid missed delivery dates

Maintenance Reasons

 Production capacity is reduced

 Orders are delayed

 No production

 Overhead continues

 Cost per unit increases

 Quality issues

 Product may be damaged

 Safety issues

 Injury to employees

 Injury to customers

Breakdown Consequences

Total Maintenance Cost

Breakdown and repair cost

Total Cost

Preventive maintenance cost

Table 14S.1

 Preventive maintenance: goal is to

reduce the incidence of breakdowns or failures in the plant or equipment to

avoid the associated costs

 Preventive maintenance is periodic

 Result of planned inspections

 According to calendar

 After predetermined number of hours

Preventive Maintenance

Frequency of breakdown

If the average cost of a breakdown is

$1,000, and the cost of preventative

maintenance is $1,250 per month, should

Example S-1

Number of breakdowns 0 1 2 3

Frequency of occurrence 20 30 40 10

Number of

Breakdowns Frequency ofOccurrence Expected number ofBreakdowns

0 1 2 3

.20 30 40 10 1.00

0 30 80 30 1.40

Expected cost to repair = 1.4 breakdowns per month X $1000 = $1400 Preventive maintenance = $1250

PM results in savings of $150 per month

Example S-1 Solution

Predictive Maintenance

 An attempt to determine when best to

perform preventive maintenance activities

 Total productive maintenance

 JIT approach where workers perform

preventive maintenance on the machines they operate

Breakdown Programs

be quickly pressed into service

 Inventories of spare parts that can be

installed as needed

 Operators who are able to perform minor repairs

 Repair people who are well trained and readily available to diagnose and correct problems with equipment

maintenance

maintenance

disruptions