The document discusses maintenance management and key maintenance strategies including breakdown, preventative, predictive, and total productive maintenance. It defines maintenance as activities that maintain facilities and equipment in working order. Breakdown maintenance reacts to problems while preventative maintenance aims to reduce breakdowns through inspection and replacement of parts. The optimal amount of preventative maintenance balances its costs with potential costs from equipment breakdown. The document also covers replacement decisions, calculating overall equipment effectiveness (OEE), and an example OEE calculation.

1. Maintenance
Management

2. Introduction
 Maintenance
◦ All activities that maintain facilities and
equipment in good working order so that a
system can perform as intended
 Breakdown maintenance
◦ Reactive approach; dealing with breakdowns
or problems when they occur
 Preventive maintenance
◦ Proactive approach; reducing breakdowns
through a program of lubrication, adjustment,
cleaning, inspection, and replacement of worn
parts

3. Maintenance Reasons
 Reasons for keeping equipment running
◦ Avoid production disruptions
◦ Not add to production costs
◦ Maintain high quality
◦ Avoid missed delivery dates

4. Breakdown Consequences
 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

5. Total Maintenance Cost
Breakdown and
repair cost
Optimum Amount of
preventive maintenance
Demand
Total Cost
Preventive
maintenance cost

6. Preventive Maintenance
 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

7. 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 use preventive maintenance?
Number of breakdowns 0 1 2 3
Frequency of occurrence .20 .30 .40 .10

8. Number of
Breakdowns
Frequency of
Occurrence
Expected number of
Breakdowns
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

9. Predictive Maintenance
 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

10. Breakdown Programs
 Standby or backup equipment that can
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

11. Replacement
 Trade-off decisions
◦ Cost of replacement vs cost of continued
maintenance
◦ New equipment with new features vs
maintenance
◦ Installation of new equipment may cause
disruptions
◦ Training costs of employees on new equipment
◦ Forecasts for demand on equipment may require
new equipment capacity
 When is it time for replacement?

12. Calculating OEE

13. OEE
The OEE calculation is based on the
three OEE Factors: Availability,
Performance, and Quality. Here's how
each of these factors is calculated.

14. Availability
Availability takes into account
Down Time Loss, and is
calculated as:
Availability = Operating Time / Planned
Production Time

15. Performance
Performance takes into
account Speed Loss, and is
calculated as:
Performance = Total Pieces / Operating
Time) / Ideal Run Rate

16. Quality
Quality takes into account
Quality Loss, and is calculated
as:
Quality = Good Pieces / Total Pieces

17. OEE
OEE takes into account all
three OEE Factors, and is
calculated as:
OEE = Availability x Performance x Quality

18.  It is very important to recognize that
improving OEE is not the only objective.
Take a look at the following data for two
production shifts.

Superficially, it may appear that the
second shift is performing better than the
first, since its OEE is higher. Very few
companies, however, would want to trade
a 5.0% increase in Availability for a 3.5%
decline in Quality

19.  Example OEE Calculation
 The table below contains hypothetical
shift data, to be used for a complete OEE
calculation, starting with the calculation of
the OEE Factors of Availability,
Performance, and Quality. Note that the
same units of measurement (in this case
minutes and pieces) are consistently used
throughout the calculations

20. OEE
Shift Length 8 hours = 480 min.
Short Breaks 2 @ 15 min. = 30 min.
Meal Break 1 @ 30 min. = 30 min.
Down Time 47 minutes
Ideal Run Rate 60 pieces per minute
Total Pieces 19,271 pieces
Reject Pieces 423 pieces

21.  Planned Production Time
= [Shift Length - Breaks]
= [480 - 60]
= 420 minutes
Operating Time
= [Planned Production Time - Down Time]
= [420 - 47]
= 373 minutes
Good Pieces
= [Total Pieces - Reject Pieces]
= [19,271 - 423]
= 18,848 pieces

22. Availability=Operating Time / Planned Production Time
373 minutes / 420 minutes=0.8881 (88.81%)
Performance=(Total Pieces / Operating Time) / Ideal Run Rate
(19,271 pieces / 373 minutes) / 60 pieces per minute=0.8611 (86.11%)
Quality=Good Pieces / Total Pieces
0.8881 x 0.8611 x 0.9780=0.7479 (74.79%)
OEE=Availability x Performance x Quality
0.8881 x 0.8611 x 0.9780=0.7479 (74.79%)