What a planned preventive maintenance schedule should contain
A PPM schedule is an asset register with tasks attached. Without the register it is a calendar of good intentions.
Planned preventive maintenance is straightforward in principle: do the work before the failure. Making that real requires more structure than a list of dates.
Start with the asset register
Every item to be maintained, identified individually: type, make, model, serial number, location, duty, installation date. Without this, tasks cannot be attached to anything and history cannot be accumulated. Most PPM schedules that fail, fail here.
Attach tasks and frequencies
For each asset, what is done and how often. Frequencies come from the manufacturer's recommendation, adjusted for how the asset is actually used and the environment it sits in. A pump running continuously in a hot plant room is not on the same cycle as an identical standby unit.
Record readings, not just attendance
The value of PPM compounds when measurements are recorded and compared visit to visit. Pressures, temperatures, currents, vibration where relevant. A single reading says whether the plant is within limits today; a trend says what will need attention in six months.
Close the loop on findings
A visit that identifies a defect has only done half the job. There needs to be a route from finding to quotation to authorisation to completion, with the defect visible until it is closed. Findings recorded on a visit sheet and never actioned are the most common failure of an otherwise functioning regime.
Review it annually
Assets are added, removed and change duty. Frequencies that were right at handover may be wrong three years on, in either direction. A schedule nobody revisits slowly stops describing the building.