Preventive maintenance planning is the part that happens before any date is chosen, and it is routinely skipped because it looks like paperwork next to the visible work of scheduling. Planning is deciding, for each recurring job, exactly what will be done, how long it takes, what parts and tools it needs, what has to be isolated, and who is competent to do it. A scheduled job that has not been planned arrives as a surprise on the day: the part is not there, the machine cannot be stopped, and the job is deferred. That deferral is not a scheduling failure. This page is about the planning that prevents it.
A task list, specific enough for somebody else to follow
Not 'service the pump'. The steps, in order, with the values to check against. This is what lets the job be done by whoever is available rather than by the one person who knows that machine, and it is the single biggest defence against a maintenance function that depends on one memory.
A duration, from measurement rather than optimism
Time a few of them. Planned durations are consistently optimistic, and a schedule built from optimistic durations is over-committed before it starts. On the worked example this site publishes, 1.1 hours a task is what makes 66 hours a month; get the duration wrong and every downstream number is wrong.
Parts and tools identified before the day
The commonest cause of a deferred PM is a part that was not to hand. Planning means the parts list exists and somebody has checked stock before the job is scheduled, which is the point at which a maintenance function and a stores function have to talk.
Access and isolation, agreed in advance
Who has to be told, what has to be stopped, what permit is needed, whose shift it affects. In a hospital or a hotel this is the constraint that decides the date; in a factory it is the shutdown. Planning it late is how a job becomes 'due, awaiting access' for three months.
Questions people ask about preventive maintenance planning
What is the difference between planning and scheduling?
Planning is what and how; scheduling is when and who. Planning is done once per task type and scheduling is done every cycle, which is why planning repays the effort.
Who should do the planning?
Somebody who has done the job, working with whoever holds the manuals. A planner who has never done the work writes durations that technicians ignore.
How detailed should a task list be?
Detailed enough that a competent technician who has not done this machine before can complete it correctly. That is a higher bar than most task lists meet and it is the right one.