What Is Planned Preventive Maintenance? Frequency, Scope and How It Is Audited

Definition at a glance

Question	Working answer
What is it?	What Is Planned Preventive Maintenance? In practical terms, what is planned preventive maintenance is a concept, institution, standard or platform that organisations must translate into owned data, controlled workflows and retrievable evidence. Its exact scope can vary by jurisdiction, activity and effective date. Verify current requirements with PPM, distinguish the formal definition from common shorthand, and record the operational consequences in the relevant business system.
Who owns it internally?	Assign the operational or compliance owner responsible for the underlying process and evidence.
What should the system hold?	Authoritative master data, dated requirements, workflow status, approvals, exceptions and retrievable evidence.
What is the main mistake?	Treating a general definition as a substitute for the current rule, standard, contract or operating context.

Use this definition as orientation. Verify current primary sources before making a regulated, financial, safety or certification decision.

This is for maintenance and reliability managers running plant in the UAE: generation and distribution, water production and pumping, district cooling, substations. It assumes you already have a CMMS full of PPMs. What it addresses is why that schedule does not hold up when someone competent asks where each frequency came from.

The register comes before the schedule

A schedule is a set of statements about specific assets. If the register is wrong, every statement inherits the error.

Two properties matter more than completeness. The first is a hierarchy that reflects function, not geography. ISO 14224:2016, third edition, sets out equipment taxonomy and attributes alongside failure cause, failure consequence, maintenance action, resources used and downtime as the minimum data to collect. A taxonomy forces you to decide what an item is before deciding how often to touch it. A pump set tagged once, and again as its motor, coupling and baseplate, accumulates maintenance history in four places and reliability history in none.

The second is tag stability. When a transformer is swapped, the PPM regime, the statutory record and the failure history attach to the position, with the serial as an attribute. Sites that tag by serial lose ten years of history in one outage. Under ISO 55001:2024 the register is also the object the asset management system is audited against.

Criticality is a decision-making tool, not a label

Criticality answers one question: how much maintenance effort is this asset worth. Score consequence across the dimensions that actually differ in your operation: supply interruption (customers affected, duration), safety, environmental release, licence exposure, replacement lead time, and whether redundancy exists and is genuinely available. An imported medium-voltage panel on a 40 week lead time behaves as more critical than its failure consequence alone suggests.

Two failure modes are common: assessing at the wrong hierarchy level, so a whole substation gets one score and the protection relay inside it inherits it; and assessing redundancy on paper, so an N+1 chiller bank scores as redundant while both units share one condenser water pump.

Four inputs to frequency, and what to do when they disagree

Every PPM frequency in a defensible schedule traces to one of four inputs, and the schedule should record which.

Manufacturer recommendation. The default, and the weakest. OEM intervals assume a generic duty cycle and environment and carry a warranty motive. In the UAE they are frequently non-conservative for anything with an air side or a filter: ambient dust loading and 45 degree summer air are not what the interval assumed.

Statutory or licence requirement. Where one exists it is a floor, not a target, and not negotiable against cost.

Criticality. Adjusts effort within the space the first two leave. High criticality justifies a shorter interval or broader task; low criticality justifies stretching, or run-to-failure with a spares strategy behind it.

Condition data. Vibration, thermography, oil analysis, partial discharge, differential pressure, motor current signature. The only input capable of telling you the other three were wrong.

When they conflict the order is fixed: statutory, then condition data, then criticality, then manufacturer. So condition data outranks the OEM interval but never the statutory one. A transformer with clean oil analysis does not escape a required electrical inspection. An OEM six-monthly filter change on a unit whose differential pressure trend says three months is an interval you override, with the trend recorded as the reason. An overridden interval with a documented basis is a professional judgement; the same override with no recorded basis is an unexplained deviation, and that is what gets written up.

The statutory layer in the UAE

Guessing here is expensive, so this is written with the gaps visible. UAE requirements split across federal instruments, emirate authorities and zone-specific regulations. An interval that binds in one jurisdiction may not bind next door.

Electrical installations, Dubai. The DEWA Regulations for Electrical Installations, 2017 Edition state that industrial and commercial installations shall at least be inspected every two years by an independent consultant or contractor, who reports findings to DEWA. For other installation types the frequency depends on the installation, its use, operation, frequency of maintenance and external influences. Testing is documented in an Inspection and Testing Certificate submitted through DEWA's Getting Electricity system, covering insulation resistance, continuity and earth electrode resistance. [NEEDS SOURCE: equivalent periodic intervals in Abu Dhabi, Sharjah and the northern emirates]

Fire and life safety. The UAE Fire and Life Safety Code of Practice, published by Civil Defence, governs. Cabinet Resolution 24 of 2012 on Civil Defence services is reported to require owners to maintain fire safety systems through accredited companies and subscribe to electronic monitoring linking buildings to Civil Defence operations centres, with a AED 10,000 fine for modifying, disconnecting, removing or covering components of an automatic fire suppression system. The UAE government portal notes Hassantuk monitoring commercial buildings and residential apartments since 2018. [NEEDS SOURCE: inspection, testing and maintenance intervals in the code by system type; dcd.gov.ae returned robots restrictions and the code text was not retrieved. Do not schedule against assumed NFPA intervals without confirming the code adopts them]

Lifting equipment. Federal intervals were not located. Within Ports, Customs and Free Zone Corporation jurisdiction, Regulation PM/004, Lifting Equipment Protocol, first edition April 2010, sets thorough examination every six months for lifting accessories, every twelve months for lifting appliances (six where the equipment lifts persons), and every six months for escalators and lifts, with proof load testing on initial supply, every four years for most equipment, and after major repair. A competent person needs at least three years hands-on experience in a relevant engineering discipline plus knowledge of the applicable laws and codes, and must be independent. Reports are retained until the equipment ceases use, or two years for accessories. Treat these as PCFC intervals, not UAE-wide. [NEEDS SOURCE: thorough examination intervals in OSHAD-SF CoP 34.0 for Abu Dhabi, and any Dubai Municipality or MOHRE federal equivalent; adphc.gov.ae returned robots restrictions]

Pressure systems. [NEEDS SOURCE: UAE statutory periodic inspection intervals for pressure vessels, boilers and air receivers. OSHAD-SF CoP 49.0 covers compressed gases and air in Abu Dhabi but its intervals were not retrieved. Do not import intervals from other jurisdictions]

Occupational safety, federal. MOHRE grounds employer duties in Federal Decree-Law 33 of 2021, requiring protection of workers from dangers arising from the use of equipment, but publishes no inspection intervals. In Abu Dhabi the OSHAD-SF framework is mandatory and risk-classified, with Codes of Practice setting minimum mandatory technical requirements by subject.

District cooling, Dubai. Executive Council Resolution 6 of 2021 requires an RSB permit alongside the commercial licence, compliance with the technical requirements in the permit addendum and RSB standards, and allows the Bureau to collect data from permit holders. Penalties run from AED 3,000 to AED 65,000, doubled for repeat offences, with suspension or revocation. Maintenance obligations therefore sit in your permit addendum rather than a public interval table, which makes the addendum a schedule input document.

Asset class, frequency driver, and the evidence the record must carry

Asset class	Typical frequency driver	Evidence a PPM record must carry
MV and LV switchgear, protection relays	Statutory (DEWA: two-yearly for industrial and commercial installations in Dubai); condition for the rest	Certificate reference, tester identity and independence, measured insulation resistance, continuity and earth values, relay settings verified against the setting sheet
Power and distribution transformers	Condition (oil analysis, thermography, partial discharge); OEM for mechanical items	Oil sample ID and lab report, dissolved gas trend against previous, tap changer operation count, bushing and cooler condition
Fire alarm, sprinkler, fire pumps	Statutory, via the UAE Fire and Life Safety Code [NEEDS SOURCE: intervals]	Approved company reference, device-level pass or fail list, pump churn and flow figures, defects with target dates
Lifting equipment and accessories	Statutory thorough examination (PM/004 in PCFC: 6 or 12 months by type; proof load every 4 years)	Competent person name and independence, report number, SWL verified, defects and time limits, next due date
Lifts and escalators	Statutory (PM/004: six-monthly in PCFC)	Examination report, safety gear and overspeed test results, next due date
Pressure vessels and air receivers	Statutory [NEEDS SOURCE: UAE intervals]; condition for corrosion	Inspection body reference, thickness readings against previous, relief valve set pressure and test date
Chillers and district cooling plant	Permit addendum, OEM, condition (approach temperature, kW/TR)	Refrigerant charge and leak check, approach temperatures, efficiency against design, any RSB-reportable event
Pumps and pump sets	Criticality plus condition (vibration, bearing temperature)	Vibration readings with route and point ID, alignment result, seal and bearing condition, running hours at service

Building the schedule

1. Freeze the register and fix the hierarchy. Reconcile the CMMS to a physical walkdown of at least the top two criticality bands, close orphan tags and duplicates, and stop new tag creation while the exercise runs. Establish parent-child relationships to a consistent level using a taxonomy such as ISO 14224, and apply one maintainable item boundary throughout.
2. Assign criticality at the maintainable item level, recording the redundancy assumption explicitly, in words, so a later reviewer can test it.
3. Build the statutory register. Per asset class: the instrument, the jurisdiction, the interval, the competent person requirement, the record format. Where you cannot source an interval, mark it open and assign an owner. Do not fill the gap with an interval from another country.
4. Set candidate frequencies from OEM manuals, recording the manual revision used.
5. Apply the resolution order. Statutory floor, then condition evidence where a history exists, then criticality. Record the driver and the reason for every frequency you changed.
6. Write the task, not the title. "Inspect pump" is not a task. The task lists steps, readings with units and limits, tools, isolation requirement, parts kit and competent person qualification. A schedule of titles produces records that prove nothing.
7. Level the load against available labour hours by trade, then against outage windows and the summer peak, when you will not take generation or cooling out of service and midday work restrictions apply.
8. Attach the spares. Define the parts kit per PPM and stock consumables at the planned frequency. A PPM whose parts arrive in eight weeks is a deferred PPM by design.
9. Publish the baseline, lock it, and set the review trigger. Version and date the schedule and require a change record for any frequency change; without a baseline you cannot detect drift. Review on asset failure, modification, condition trend breach, statutory change, or a fixed annual cycle, whichever comes first.

Labour and spares against the schedule

The schedule is a demand forecast. Convert it: PPM hours by trade by month against establishment hours net of leave, training and the corrective work you know will arrive. Where it demands more hours than exist, compliance gets achieved by deferral rather than by work. Plan to realistic wrench time rather than nominal hours, because travel, permits, isolation and waiting on operations consume most of a shift on distributed assets. And carry the parts kit as a kit: a PPM needing eleven line items against eleven separate reservations is blocked by the one item nobody noticed was at zero.

The metrics that get audited, and how they are gamed

Three are always asked for, and all three are gameable.

PPM compliance (completed on time divided by due) is gamed by rescheduling before the due date passes, so the work moves and the metric never records a miss. The audit test is not the percentage; it is the count of due-date changes made after the PPM was raised, and by whom.

Schedule compliance (work completed from the frozen weekly plan divided by work in that plan) is gamed by planning only what is certain to happen, producing a small plan at 100 per cent. Test it against schedule loading, planned hours over available hours: high compliance on a plan loaded at 40 per cent means nothing.

Backlog is gamed by closing work orders that were not done and raising new ones, resetting age while the work stays undone. Test the distribution of backlog age, not the total, and sample closed PPMs for evidence of execution. Under all three sits the same failure: a completion tick with no readings. An auditor who finds one blank reading field will assume the rest.

Schedule drift

A PPM plan built two years ago does not match the plant, for reasons that are individually reasonable and collectively fatal.

Plant changes and the register does not: pumps re-impelled, drives replaced with VSDs, a chiller retrofitted with a different compressor, while the PPM still references the superseded manual. Duty changes, so an asset built for standby now runs base load on an interval set for the old duty. Frequencies get stretched under labour pressure and never reviewed when headcount recovers. Statutory instruments are updated and nobody re-reads the schedule against them.

The counter is a versioned baseline plus a change record, so drift shows as a diff rather than surfacing in an incident investigation. If you cannot answer "what changed in this schedule since last year and who approved it" in under an hour, you have drift you cannot see.

Where teams get this wrong

Copying intervals across jurisdictions. A frequency verified for Dubai, or for a PCFC free zone, gets applied estate-wide. It may be over-maintenance in one place and non-compliance in another, and the second is what gets found.

Confusing statutory inspection with PPM. A statutory examination frequently requires an independent competent person; your own technician closing it in the CMMS does not satisfy it, however well the task was done.

Treating the OEM manual as the answer. Manuals get filed at handover and never revised, so six years later the schedule reflects a revision superseded twice.

Scoring criticality once. Consequence changes when the network changes. A feeder that was one of three is now one of two.

Letting condition monitoring run parallel to the schedule. Where the vibration route and the PPM plan are separate systems, the analyst's finding never changes an interval. Condition data that cannot alter a frequency is a report, not a strategy.

What to automate, and what not to

Automate the arithmetic and the evidence: generating PPMs from frequency and last-completed date, blocking closure until mandatory readings are entered, holding statutory due dates against competent person certification so an expired examiner cannot sign, versioning and diffing the schedule, and computing loading and backlog age honestly rather than as headline percentages.

Do not automate the frequency decision. A system that proposes intervals from failure history will be confidently wrong on assets with few failures, which is most critical plant, and it cannot read your district cooling permit addendum or a Civil Defence circular. Setting a frequency is an engineering judgement made by someone accountable for it. What software should enforce is that the judgement was recorded at all.

Where a system helps

The value of an asset management system here is not scheduling; a spreadsheet schedules. It is holding the chain from asset tag through criticality, frequency, driver, task steps, mandatory readings, executing person and certificate to the audit evidence pack. That chain breaks when a plan is spread across a CMMS, a shared drive of PDFs and a vibration database.

KreupAI's eAMS is built for that chain, including the case where statutory and OEM intervals disagree and the override needs a recorded reason. It does not tell you what the statutory intervals are; those come from the instruments applying to your emirate and zone, and belong in your statutory register with an owner against each.

Related reading: KB-129 and KB-130.

FAQ

Can condition monitoring replace a time-based PPM? It can replace an OEM-driven one where the failure mode is detectable and the gap between detection and functional failure is long enough to act. It cannot replace a statutory inspection, which binds regardless of asset condition.

What is a realistic PPM compliance target? Any target set without publishing schedule loading alongside it invites gaming. Report compliance, loading and backlog age together, and treat high compliance on a plan loaded above 100 per cent as evidence of deferral rather than performance.

Where do I find the statutory intervals for my UAE site? Build a statutory register per emirate and per zone rather than assuming a federal rule. Confirmed here: DEWA's two-yearly inspection in Dubai, and PM/004's lifting intervals within PCFC jurisdiction. Fire and life safety, pressure systems and Abu Dhabi lifting intervals need confirming against the source instrument.

Should the CMMS hold statutory records, or a separate compliance register? One record, referenced from both views. Where they are separate the statutory due date drifts from the PPM due date, and the version an inspector sees is whichever somebody remembered to update.

Sources

• DEWA, Regulations for Electrical Installations, 2017 Edition
• Dubai Civil Defence, UAE Fire and Life Safety Code of Practice
• UAE Government Portal, Fire safety
• General Command of Civil Defence, Circular on Passive Firestopping Systems (March 2023)
• PCFC / Dubai World, Regulation PM/004 Lifting Equipment Protocol
• Abu Dhabi Public Health Centre, OSHAD-SF Manual
• RSB Dubai, Executive Council Resolution 6 of 2021 on District Cooling
• MOHRE, Occupational Health and Safety guidance
• ISO 14224:2016
• ISO 55001:2024
• Abu Dhabi Department of Energy, Laws and Regulations