Walk into any maintenance conference and you’ll hear it: “World-class is 85% planned and 15% reactive.” Or “80/20.” Or “90% proactive.”
The trouble is not that every number is invented. It is that the numbers often come from different metrics and get presented as if they form one clean ratio.
Under SMRP’s framework, planned and unplanned work are one pair. Proactive and reactive work are separate measures with different definitions. Reactive work is tied to disruption of the weekly schedule, not simply to whether an asset failed. And none of those labor-hour targets automatically becomes a planned-versus-reactive spending benchmark.
That distinction matters. A planned job can still be reactive if it breaks the weekly schedule. A repair after a failure can later be planned and scheduled through the normal process. Calling all failure work “reactive” and all planned work “proactive” blends metrics that were designed to answer different questions.
This is a reality check on the ratios people quote, what the recognized metrics actually measure, and how to discuss maintenance spending without overstating the evidence.
What the Metrics Actually Measure
The familiar slogans usually combine four different concepts.
Planned Work (SMRP Metric 5.3.1). This measures maintenance labor hours spent on planned jobs as a percentage of total maintenance labor hours. Commonly cited targets put planned work around 80% to 90%, though the exact best-in-class figure varies by source and SMRP edition. Planned Work pairs with Unplanned Work; it is not the opposite of Reactive Work.
Proactive Work (SMRP Metric 5.4.2). This measures labor hours spent on preventive maintenance, predictive maintenance, and corrective work identified through those activities and completed before functional failure. Targets are commonly cited around 80% or higher.
Reactive Work (SMRP Metric 5.4.1). SMRP defines reactive work as maintenance work that interrupts the weekly schedule. It is measured as a percentage of total maintenance labor hours, with best-in-class commonly cited below 10%, though some SMRP material puts it below 5%. That is narrower than the everyday use of “reactive,” which often means any repair performed after a failure.
Scheduled Work and Schedule Compliance. These are different again. Planning develops the job scope, labor, materials, tools, and instructions. Scheduling assigns ready work to a specific period and available workforce. As Doc Palmer emphasizes, planning and scheduling are related but separate disciplines.
Four concepts, several denominators, one industry slogan. That is where the confusion starts.
Maintenance Ratios: What Holds Up
Reliable Confidence Score: how safely each figure can be used in a maintenance and reliability discussion, based on source quality, definition clarity, and the risk of misquotation.
Reliable Confidence Score: how safely each figure can be used in a maintenance and reliability discussion, based on source quality, definition clarity, and the risk of misquotation.
| Source or Claim | Figure | Reliable Confidence | What It Really Means |
|---|---|---|---|
| SMRP Planned Work, Metric 5.3.1 | Commonly cited target around 80% to 90% planned | Mediumtarget is convention | Planned maintenance labor hours divided by total maintenance labor hours. It pairs with Unplanned Work. The metric and definition are confirmed; the exact best-in-class figure is industry convention, not a verified SMRP number. |
| SMRP Proactive Work, Metric 5.4.2 | Commonly cited target around 80% or higher | Mediumtarget is convention | PM, PdM, and corrective work found through PM/PdM and completed before failure, measured in labor hours. The metric and definition are confirmed; the exact target is industry convention. |
| SMRP Reactive Work, Metric 5.4.1 | Commonly cited below 10%; some SMRP material cites below 5% | Mediumtarget varies by edition | Work that interrupts the weekly schedule, measured in labor hours. It is not synonymous with run-to-failure. Published SMRP targets range from below 5% to below 10% depending on the document. |
| “80% planned, 20% reactive” | Commonly quoted target | Low | It combines metrics that are not complementary under SMRP. Use it only after defining exactly what each bucket contains. |
| “90% planned, 10% reactive” | Common world-class slogan | Mediumat best | The individual figures resemble SMRP-style targets, but they do not form one SMRP ratio. Planned Work pairs with Unplanned Work, while Reactive Work measures schedule interruption. |
| Plant Engineering 2022 survey | Average asset coverage: 35% reactive, 38% preventive, 14% predictive, 10% reliability-centered | Highdenominator caveat | This describes how respondents said their asset bases were maintained. It is not a labor-hour, work-order, or spending ratio. |
| Universal planned-versus-reactive spending benchmark | No such target was located in the cited standards | Highnarrowly stated | SMRP and EN 15341 include cost-related KPIs, but neither cited framework supplies a universal target dividing maintenance spending into planned and reactive buckets. |
| “Reactive maintenance costs three to five times more” | Common cost multiplier | Low | The exact multiplier is widely repeated but is not supported by the cited standards or DOE guide. It should not be presented as a universal fact. |
The Big Takeaway
There is no single defensible “planned-versus-reactive ratio” unless the organization first creates and documents its own mutually exclusive categories.
The recognized SMRP targets answer different questions:
- Planned Work: commonly cited around 80% to 90%
- Proactive Work: commonly cited around 80% or higher
- Reactive Work: commonly cited below 10% (some SMRP material says below 5%)
Treat those targets as commonly cited convention. The current SMRP best-in-class figures sit behind a paywalled edition, and open SMRP material gives varying thresholds, so the metric definitions are firmer ground than any single percentage.
Those figures should be reported separately, with the metric name, formula, denominator, and measurement period attached.
Planned, proactive, and reactive are not interchangeable labels for the same two buckets.
This also changes how the spending question should be handled. Both SMRP and EN 15341 contain economic or cost-related indicators, but the cited frameworks do not publish a universal target stating that a certain percentage of maintenance dollars should be planned and the rest reactive.
A plant can calculate that split internally, but it is a site-specific management measure rather than a recognized benchmark.
Why the Numbers Disagree
Four issues turn one slogan into a dozen conflicting answers.
The categories are not opposites. Planned Work pairs with Unplanned Work. Proactive Work is built from PM, PdM, and qualifying corrective work. Reactive Work is based on interruption of the weekly schedule.
“Reactive” has two meanings. In everyday plant language, it often means work after failure. In SMRP Metric 5.4.1, it means work that breaks the weekly schedule. Those populations overlap, but they are not identical.
The denominator changes. A percentage may be based on labor hours, work-order count, asset coverage, direct maintenance cost, or total business impact. The same operation can look very different under each denominator.
Cost boundaries change. Direct maintenance spending includes items such as labor, materials, contractor charges, and expedited freight. Lost production, quality losses, safety exposure, and collateral damage are business consequences. They matter, but adding them to maintenance spending creates a different measure.
What the Cost Evidence Supports
Unplanned and emergency work can create overtime, expedited purchasing, inefficient labor use, secondary damage, and production disruption. The direction of the cost argument is credible.
The size of the multiplier is not universal.
The US Department of Energy’s Operations & Maintenance Best Practices Guide describes reactive maintenance as a high-cost approach and cites estimated savings of roughly 12% to 18% when preventive maintenance replaces reactive maintenance in the facility context discussed. The guide also makes clear that the estimate is not universal.
The cost penalty is real; the universal multiplier is not.
That evidence does not support the blanket statement that every reactive job costs three to five times as much as a planned job. The actual difference depends on asset criticality, failure mode, labor arrangements, parts availability, production constraints, and what costs are included.
How to Measure the Ratios Without Creating Bad Data
Start with the standard metrics rather than inventing one blended score.
- Define Planned Work, Unplanned Work, Proactive Work, and Reactive Work separately.
- Use maintenance labor hours as the denominator when following the SMRP definitions.
- Establish and freeze the weekly schedule so Reactive Work can be measured consistently.
- Record the source of corrective work: PM finding, PdM finding, operator observation, failure, or another trigger.
- Report asset-strategy mix separately from work-execution metrics.
- Reconcile definitions whenever comparing plants, business units, or external benchmarks.
For the spending question, create a separate site-specific model.
Direct maintenance spending may include regular and overtime labor, materials, contractors, rentals, and expedited freight. Business consequence cost may include downtime, lost throughput, quality losses, collateral damage, and safety or environmental impacts. Report the two separately before combining them into a broader event-cost measure.
That approach produces a useful internal spending ratio without presenting it as an external standard.
Where Teams Go Wrong
Mixing Planned Work and Reactive Work as one ratio. Under SMRP, they do not form a complementary pair.
Calling all post-failure work reactive. That may match local language, but it is not the definition used by SMRP Metric 5.4.1.
Using an asset-strategy survey as a labor benchmark. The Plant Engineering figures describe percentages of assets managed under different approaches, not percentages of maintenance hours or dollars.
Calling production loss maintenance spending. Production loss belongs in a consequence or total-event-cost calculation unless the organization explicitly defines a broader cost measure.
Quoting the three-to-five-times multiplier as fact. It may be useful as a discussion prompt, but the exact multiplier needs site data or a source tied to a specific operating context.
Methodology
This article separates the defined maintenance-work metrics from the informal ratios used in industry conversation.
The metric names, formulas, and definitions follow SMRP Best Practices guidance for the Work Management pillar, including Planned Work (5.3.1), Reactive Work (5.4.1), and Proactive Work (5.4.2). Those metric numbers appear in SMRP’s own metrics workshop materials and training catalog. The best-in-class targets, however, are reported here as commonly cited ranges, because the current SMRP figures sit behind a paywalled edition and open SMRP material gives varying thresholds (for example, reactive work below 5% in one document versus below 10% elsewhere). The planning-versus-scheduling distinction is supported by Richard “Doc” Palmer’s Maintenance Planning and Scheduling Handbook, Fourth Edition.
EN 15341:2019+A1:2022 was reviewed as the current European maintenance KPI standard. It includes economic, technical, and organizational indicators, but no universal planned-versus-reactive spending target was located in the cited standard.
The Plant Engineering comparison uses its 2022 maintenance survey article and preserves the survey’s asset-coverage denominator. The cost discussion uses the DOE guide as directional evidence and does not treat its facility-level estimate as a universal benchmark.
Bottom Line
The safest approach is to quote the named SMRP metrics by their definitions: Planned Work (versus Unplanned Work), Proactive Work, and Reactive Work as schedule interruption. Commonly cited targets put planned work around 80% to 90%, proactive work around 80% or higher, and reactive work below 10%, but treat those figures as convention rather than a verified SMRP best-in-class number.
Do not combine them into a single planned-versus-reactive ratio without creating mutually exclusive local categories. Do not convert labor-hour targets into dollar targets. And do not present an internal spending split or a three-to-five-times cost multiplier as an industry standard.
Name the metric, state the denominator, and define the cost boundary. Once those three things are clear, the number has a chance to mean what the speaker thinks it means.
Sources
- Society for Maintenance & Reliability Professionals (SMRP), Best Practices, Metrics & Guidelines, Sixth Edition overview: https://smrp.org/Learning-Resources/SMRP-Library/Best-Practices-Metrics-Guidelines
- SMRP, Metric 5.3.1 — Planned and Scheduled Work MicroLearning: https://training.smrp.org/products/metric-531-planned-and-scheduled-work-microlearning
- SMRP, Metric 5.4.1 — Reactive Work MicroLearning: https://training.smrp.org/products/metric-541-reactive-work-microlearning
- SMRP, Metric 5.4.2 — Proactive Work MicroLearning: https://training.smrp.org/products/metric-542-proactive-work-microlearning
- Richard D. Palmer, Maintenance Planning and Scheduling Handbook, Fourth Edition (McGraw-Hill, 2019): https://www.mheducation.com/highered/mhp/product/maintenance-planning-scheduling-handbook-4th-edition.html
- BSI, BS EN 15341:2019+A1:2022 — Maintenance: Maintenance Key Performance Indicators: https://knowledge.bsigroup.com/products/maintenance-maintenance-key-performance-indicators-2
- Plant Engineering, Jobs Are There for the Taking (June 10, 2022), reporting maintenance-strategy shares across respondents’ asset bases: https://www.plantengineering.com/articles/jobs-are-there-for-the-taking/
- US Department of Energy, Federal Energy Management Program, Operations & Maintenance Best Practices Guide, Release 3.0: https://www.energy.gov/sites/prod/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf
