Preventive Maintenance (Maintenance Strategy Series Volume 1)
Book Review: Maintenance Strategy Series Volume 1 – Preventive Maintenance
Overview
This is a practical how-to book for building or improving an industrial preventive maintenance program.
The fact that Wireman kicks his Maintenance Strategy Series off with preventive maintenance as the foundation is a statement in itself. Compared to RCM and condition monitoring technologies, preventive maintenance is often given relatively little attention. Yet this book makes the nuanced argument that a neglected, irrelevant preventive maintenance program is symptomatic of a cultural deficiency in the workplace. If a basic preventive maintenance program can not be established and made effective, then the organization is not disciplined enough to make more complicated approaches work.
Preventive maintenance is defined broadly to include tasks related to
- Inspections
- Adjustments
- Lubrication
- Proactive replacements
Success is established and the organization can move on when unplanned (reactive) equipment maintenance is less than 80% of total maintenance man-hours.
The PM Cycle of Doom
Wireman’s description of the preventive maintenance cycle will make most maintenance professionals either laugh or cry, but it will be familiar.
Someone notices that equipment is always breaking down, so a preventive maintenance program is created. Through years of refinement, reliability improves. Once reliability improves, the accountants ask why so much money is being spent on maintenance—and the maintenance budget is cut, leading to reduced availability.
Hence, upper management support is considered necessary for the success of a program. However, chapter 1—on the importance of preventive maintenance, offers a helpful list of reasons to stick with the program.
Key Points
- When looking at failure curve distributions produced by the Nowlan & Heap study (shown right), one would assume that preventive maintenance has a relatively small role in reliability improvement. However, most of the failure modes skewed toward the non-age-related side are related to electronics. There are still a lot of failures to prevent on the age-related side.
- PM programs address normal wear-out issues. Abuse/misuse can not be addressed through preventive maintenance. [I would argue that a strong maintenance culture with sharing of knowledge of what causes equipment failure will reduce abuse/misuse failures. Therefore, a strong maintenance culture indirectly reduces those failures.]
- Cost effective maintenance is the result of a balance between too much maintenance (high maintenance costs and low operational costs) and too little maintenance (low maintenance costs and high operational costs). Theoretically, there is an optimum that can be found and exploited.
- What needs to be managed must be measured. Therefore, metrics for preventive maintenance include % downtime caused by breakdowns, % man-hours spent on emergency jobs, % maintenance budget spent on breakdown work, % preventive tasks completed vs. scheduled, PM task cost estimate as a % of actual, % breakdowns that should have been caught by a PM program, % work orders generated from PM inspections, equipment uptime, % of PMs overdue, and % overtime hours. Some of these are difficult to measure and require a concerted effort at RCA.
- Anticipate and address PM program problems. These are lack of management support, maintenance skill gaps, selecting the wrong equipment, not updating PMs, lack of detail, not recording PM data, and not understanding regulations.
Useful Features
At first reading, I was afraid that the book was lacking in specific examples. Upon reaching the appendices, I was corrected. One of the most useful features of the book is the appendices. Much of the general principle discussed earlier in the book is given detailed attention at this point.
Appendix A contains sample operator inspections for belt drives, chain conveyors, chain drives, conveyors, gear cases, hydraulic lifts, hydraulic motors, pneumatic cylinders, and pneumatic motors.
Appendix B contains system inspections for typical motor/gearcase combinations, belt drives, chain drives, belt conveyors, chain conveyors, hydraulic lifts, hydraulic motor circuits, pneumatic cylinders, pneumatic motors, electrical starters, lighting circuits,and motor-generator sets.
Appendix C contains component inspections and procedures for air compressors, gearboxes, motor control centers, pump packings, switchboards, switches, starters, and v-belts.
With minimal customization, the material in these appendices could be taken straight out of the book to expedite the implementation of a thorough PM program.
Table of Contents
Introduction
Overview: The Maintenance Strategy Series Process Flow
Chapter 1: Why Preventive Maintenance is Important
Chapter 2: Developing the Preventive Maintenance Program
Chapter 3: Identifying the Equipment to Include in a Preventive Maintenance Program
Chapter 4: How to Develop PM Requirements for the Equipment
Chapter 5: How to Develop PM Task Sheets
Chapter 6: Determining the Skill Requirements for PM Tasks
Chapter 7: Determining the Parts Requirements for PM Tasks
Chapter 8: Determining the Scheduling Requirements for PM Tasks
Chapter 9: Executing Preventive Maintenance Tasks
Chapter 10: Consistent PM Program Follow-up
Chapter 11: Performance Management for PM Programs
Appendix A: Sample Operator Inspections
Appendix B: Developing System PM Inspections
Appendix C: Sample Component PM Inspections
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