Page 413 - Intro Predictive Maintenance

404 An Introduction to Predictive Maintenance

Table 18–1 Twelve-Point Data Collection Process Facilitates Analysis of OEE Information

Overall Equipment Effectiveness
1. Planned Time Available 7,200 minutes
8 hours ¥ 60 minutes = 480 minutes ¥ 15 turns or shifts
2. Planned Downtime 250 minutes
For preventive maintenance, lunch, breaks, etc.
3. Net Available Run Time 6,950 minutes
Item 1 - Item 2
4. Downtime Losses 4,640 minutes
Breakdowns, setups, adjustments
5. Actual Operating Time 2,310 minutes
Item 3 - Item 4
6. Equipment Availability 33%
Item 5
¥100
Item 3
7. Total Output for Operating Time 15,906 units
Total produced in units, pieces, tons, etc.
8. Design Cycle Time 0.109 minutes/unit
9. Operational Efficiency 75%
Item 8 ¥ Item 7
¥100
Item 5
10. Rejects During Turn (Shift) 558 units
11. Rate of Product Quality 96.8%
Item 7 Item 10
-
¥100
Item 7
12. OEE 23.96%
Item 6 ¥ Item 9 ¥ Item 11

equipment effectiveness in most U.S. companies barely breaks 50 percent. It is little
wonder that there is so much room for improvement in typical equipment maintenance
management programs.

A plastic injection molding plant had a press with the following statistics:

• The press was scheduled to operate 15 eight-hour shifts per week.
• This gave a total possibility of 7,200 minutes of run time per week.
• Planned downtime for breaks, lunches, and meetings totaled 250 minutes.
• The press was down for 500 minutes for maintenance for the week.
• The changeover time was 4,140 minutes for the week.
• The total output was 15,906 pieces.
• The design cycle time was 9.2 pieces per minute.
• There were 558 rejected pieces for the week.
• What is the OEE for the press for the week in question?

A form to collect and analyze OEE information is pictured in Table 18–2. The
equipment availability is calculated in the first section of the form. The gross time