Why this book matters
Walk any plant and you'll find a crew that is genuinely busy - and a backlog that never shrinks. The crusher PM slips again, the conveyor splice waits for a crane that was never booked, and the fitter spends the morning hunting a gasket for the pump he opened an hour ago. Nobody is lazy. The system is just burning hours between jobs.
Doc Palmer's handbook - first published in 1999, now in its 4th edition and roughly 900 pages - is the reference on fixing exactly that. Palmer spent years running planning groups in power utilities before writing down what actually works. His argument is brutal and liberating at the same time: the biggest capacity increase available to almost every maintenance department is not a new hire, a new CMMS or a new sensor. It's the paid hours already walking around the plant, unlocked by planning and scheduling done properly.
Strategy tells you what work is worth doing - that's RCM territory (see our RCM II summary). Palmer's book is about the other half nobody glamorizes: getting that work executed efficiently, week after week.
Core idea
Planning does not make technicians work harder. It removes the waiting. Same crew, same effort, same pace on the tools - but the delays between jobs (parts, scope, permits, travel, cranes) get engineered out in advance. That is where the extra capacity comes from.
The wrench-time revelation
Wrench time (or "tool time") is the share of a technician's paid day spent hands-on-tools, actually advancing a job. Work-sampling studies keep finding the same uncomfortable numbers: reactive, unplanned sites typically run at 25-35%. World-class planned-and-scheduled sites reach ~50-55%. Nobody gets 100% - people legitimately need breaks, travel and instructions. But the gap between 30% and 55% is pure, recoverable waste.
Now run the math that made this book famous. Take a crew of 10 technicians at 30% wrench time: you get 3 "technician-equivalents" of actual work per day. Lift the same crew to 55% and you get 5.5 - an 83% increase in hands-on capacity without hiring anyone. Going from 30% to 55% is like adding 8 technicians to a crew of 10, for the cost of one planner's salary.
And here's the part managers get wrong: you cannot get there by pushing people. A fitter standing at the store counter waiting for a mechanical seal is not being lazy, and yelling at him doesn't make the seal appear. The delay was baked in the moment the job was issued without a kitted part, a scoped procedure or a booked crane. Wrench time is a property of the work system, not of the workers.
The 6 principles of planning
Palmer's first six principles define what a planner is - and, just as importantly, what a planner is not. Most "failed" planning programs violate at least three of these on day one.
| # | Principle | The waste it kills on site |
|---|---|---|
| 1 | Planners sit in a separate department, not inside the craft crews. | The planner being pulled in as an extra pair of hands every time the crusher trips - and planning dying within a month. |
| 2 | Planners focus on future work only - never on jobs already in progress. | The black hole of chasing parts and answers for today's breakdowns, which one person can do for one crew but never for thirty techs. |
| 3 | Component-level job files, filed by equipment tag, so every repeat job starts from the last one. | Re-inventing the gearbox swap on conveyor CV-201 from scratch every 18 months, including re-discovering the special puller it needs. |
| 4 | Estimates come from planner expertise, not from padded engineered standards. | Weeks of arguing over "standard hours" that everyone knows are fiction - and estimates nobody trusts or uses. |
| 5 | Recognize the skill of the craft. Plans give scope, parts and the right procedures where needed - not micro-instructions. | 40-page work packs for a coupling alignment that insult the tradesman and never get read. |
| 6 | Measure performance with wrench time. | "We feel busier than ever" as the department's only performance metric. |
Field tip
Principle 2 is where programs live or die. The day your planner gets dragged into expediting a bearing for the compressor that's down right now, next week just lost its plans - and next week's crew will wait like this week's did. Protect the planner from today, so the whole crew wins tomorrow. Urgent jobs still get done; they just don't consume the planning function.
The 6 principles of scheduling
Planning prepares individual jobs. Scheduling is what forces enough of them into the week. Palmer's insight: without a schedule, Parkinson's law eats the savings - the work expands to fill the time available.
- Job plans with time estimates - you cannot schedule work you haven't sized. Every planned job carries craft, headcount and estimated hours.
- Schedules and priorities matter - the weekly schedule is a commitment the whole plant respects, filled from the highest-priority backlog, not from whoever shouts loudest.
- One-week horizon - a scheduler builds next week's schedule from the forecast of available craft hours. A week is short enough to be realistic, long enough to coordinate parts and access.
- Schedule to 100% of forecast capacity - the counterintuitive one. Load every forecast hour, even knowing break-ins will come. Under-loading "to leave room for emergencies" just guarantees the crew drifts back to reactive pace.
- The crew supervisor handles the daily schedule - dispatching people job by job is the supervisor's game, played one day ahead. The scheduler sets the week; the supervisor plays the day.
- Measure schedule compliance weekly - the schedule is a commitment device, not a straitjacket. Break-ins are allowed; they are also counted, so every Friday you know exactly how much of the week reactive work stole.
Principle 4 is the one that gets challenged in every workshop, so here's the logic: if you schedule 80% of capacity, you get at best 80% minus the break-ins. If you schedule 100%, break-ins still happen - the lowest-priority scheduled jobs simply slide - but the crew starts each day with a full plate of ready-to-go work. The goal of 100% loading isn't 100% compliance; it's maximum work issued. Compliance is the measurement, not the target to protect by gaming the load.
Notice what the cycle does not contain: nobody asks technicians to hurry. The crusher liner change takes the hours it takes. What changes is that when the liner crew finishes at 2 p.m., the next kitted job is already in their hands instead of being negotiated at the store counter until 3:30.
The planner leverage math
Why does one salaried planner beat one more technician, every time? Leverage.
One good planner supports 20 to 30 technicians. If planning and scheduling lift that group's wrench time from 30% toward 55%, the gained capacity is worth the equivalent of several extra technicians - on a 30-tech crew, well over a dozen technician-equivalents of hands-on work. No other maintenance hire comes close to that return. Hiring one more fitter adds one fitter; hiring one planner multiplies everyone else.
The leverage only pays out if the function survives contact with reality. Palmer is blunt about the classic failure modes, and you will recognize your site in at least one:
- Planners as parts-chasers. The planner becomes a storeroom expediter for jobs in progress. Leverage: zero.
- Planning jobs in progress. Feels helpful, burns the whole week, plans nothing for next week.
- Estimates as time cards. The moment estimates are used to police individual technicians, the crew fights the numbers instead of the backlog.
- Measuring nothing. No wrench-time sampling, no schedule compliance - so nobody can prove the program works, and the next budget cut takes the planner first.
That last point is why planning and scheduling can't live without a small set of honest metrics - schedule compliance, planned-work ratio, backlog weeks. For how to build that measurement layer without drowning in dashboards, see our Wireman KPI summary.
Using it in 2026
The principles have barely aged. The tooling around them has changed completely.
| Keep as-is | Update with modern practice |
|---|---|
| The 6+6 principles. Separation of planning from execution, future-work focus, 100% loading, weekly compliance - none of this depends on technology, and none of it has been improved on. | Job plan authoring. The historical bottleneck was planner typing time. AI can now pre-draft job plans from OEM manuals, old work orders and the equipment file - the planner reviews and fixes instead of writing from a blank page, and the component-level library (principle 3) builds itself years faster. |
| Wrench time as the honest yardstick. Still the only metric that measures the work system instead of the workers. | How you sample it. Classical work sampling means weeks with a clipboard. Mobile CMMS status updates and digital work orders now give a continuous, cheap proxy - calibrate it once against a proper sampling study, then track the trend. |
| The weekly schedule as a plant-wide commitment between maintenance and operations. | What feeds the schedule. In 1999 the backlog came from operator rounds and PMs. In 2026, condition monitoring and RCM-derived strategies (see our RCM II summary) push predictive work into the backlog early - planning is what turns an alarm into a kitted, scheduled job instead of a 2 a.m. call-out. |
Bottom line
Buy the sensor later. If your wrench time is 30%, the cheapest capacity on earth is already standing in your workshop wearing your logo. Read Palmer for the operating model, then use 2026 tools to run it with a fraction of the historical admin effort.
References & further reading
This summary is original explanatory writing. All concepts belong to their authors - go to the sources.
- Palmer, R.D. Maintenance Planning and Scheduling Handbook, 4th edition. McGraw-Hill Education, 2019. ISBN 978-1-260-13528-2. Publisher page (McGraw Hill)
- Palmer, R.D. Articles, videos and course material on planning and scheduling at the author's site. palmerplanning.com
- SMRP. Society for Maintenance & Reliability Professionals - harmonized definitions for schedule compliance, planned-work ratio and related work-management metrics. smrp.org
- Wireman, T. Developing Performance Indicators for Managing Maintenance, 2nd edition. Industrial Press, 2005 - the companion measurement layer. Our summary · Book page
Disclaimer. This page is an independent educational summary written entirely in Rob Reliability's own words. It is not affiliated with, sponsored by or endorsed by Richard "Doc" Palmer, Richard Palmer and Associates or McGraw-Hill Education. No text from the original book is reproduced; all diagrams are our own original illustrations of engineering concepts that are part of the public technical literature. Book titles, trade names and trademarks remain the property of their respective owners and are used solely to identify the work being discussed. If you are a rights holder and have any concern about this page, contact us at hello@robreliability.com and we will address it promptly.
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