When should you use a run-to-failure strategy?

Use run-to-failure when a failure is safe, cheap, and does not stop production, and when preventing it would cost more than it saves. The best candidates are low-criticality assets that are redundant, inexpensive to replace, quick to repair, and fail randomly with no useful warning, such as non-critical lighting, cheap fail-safe sensors, and redundant pumps with an auto-starting standby.

Is run-to-failure ever the right choice?

Yes. Run-to-failure is one of the four core maintenance strategies and the correct, lowest-cost choice for low-criticality assets. Department of Energy benchmarks put a healthy maintenance mix around 10 to 15 percent reactive, meaning a well-run plant still runs some assets to failure on purpose. A program with zero run-to-failure is usually over-maintaining cheap equipment.

What is the risk of run-to-failure maintenance?

The main risk is accidental run-to-failure: assets nobody chose to run to failure but nobody maintains either, which quietly pile up as deferred-maintenance risk until one breaks at the worst time. Applying run-to-failure to a high-consequence asset is also dangerous, because the failure cost, safety risk, and collateral damage far outweigh any preventive savings.

How do you decide which assets to run to failure?

Rank each asset's criticality, then compare the annual cost of preventing failure against the expected cost of the failure itself. If the asset is low-consequence, cheap to replace, quick to fix, and fails randomly with no warning, and prevention costs more than the failures it avoids, run-to-failure is the right call. Record the decision so it stays deliberate.

How much does reactive maintenance cost compared to preventive?

The Department of Energy's O&M Best Practices guidance estimates that a preventive maintenance program saves roughly 12 to 18 percent over a reactive run-to-failure program for assets that warrant prevention, with predictive maintenance saving a further 8 to 12 percent. Reactive failures also carry hidden costs like overtime, expedited parts, and secondary equipment damage.

Run-to-Failure Maintenance: When It Makes Sense

Q: What is run-to-failure maintenance?

Run-to-failure maintenance is a deliberate strategy where an asset is intentionally operated with no preventive intervention until it fails, then repaired or replaced. It is chosen on purpose for low-criticality, low-cost, redundant, or randomly failing assets where preventing the failure would cost more than the failure itself. The failure is expected and planned for, not a surprise.

Q: Is run-to-failure the same as reactive maintenance?

No. The difference is intent. Deliberate run-to-failure is a chosen strategy for assets you analyzed and decided not to maintain, with spares stocked and a repair plan ready. Reactive or breakdown maintenance is unplanned failure of assets you never made a decision about, so every failure is a costly surprise with no spare and often collateral damage.

Running an asset until it breaks sounds like neglect. Chosen on purpose for the right equipment, it is the cheapest correct answer. Here is how to tell the two apart.

Run-to-failure maintenance is a deliberate strategy where you choose to operate an asset until it breaks, then repair or replace it, because doing so costs less than preventing the failure. It is a planned decision for low-criticality, cheap, redundant, or unpredictable assets, not the same as neglect.

The phrase "run to failure" makes many reliability people flinch, because it sounds like an excuse for doing nothing. Done on purpose, for the right assets, it is the opposite: it is the cheapest correct answer. The mistake is not using run-to-failure. The mistake is defaulting to it for everything by accident. This guide draws the line between deliberate RTF and reactive breakdown maintenance, shows when RTF is the right call, and lays out how to set it up so it stays a choice instead of a surprise.

What is run-to-failure maintenance?

Run-to-failure (RTF) maintenance is a strategy in which an asset is intentionally operated with no preventive intervention until it fails, at which point it is repaired or replaced. The key word is intentionally. In a true RTF strategy, someone looked at the asset, weighed the cost of preventing failure against the cost and consequence of the failure itself, and decided that letting it run to breakdown is the lower-cost path. The failure is expected, planned for, and absorbed on purpose.

That decision only holds when the failure is safe, cheap, and does not stop production. A hallway light bulb is the textbook example: you do not inspect it, lubricate it, or replace it early. You let it burn out, then swap it. The failure hurts nothing, the part is cheap, and a spare sits on the shelf. Extend that logic to industrial assets that share those traits and RTF becomes a legitimate, even optimal, choice. The strategy shows up in every serious reliability framework precisely because not every asset earns preventive attention.

Is run-to-failure the same as reactive maintenance?

No, and the difference is intent. Deliberate run-to-failure is a chosen strategy for assets you have analyzed and decided not to maintain. Reactive maintenance, also called breakdown maintenance, is what happens when assets fail that you never made a decision about, so every failure is a surprise that interrupts the day. They can look identical at the moment the machine breaks, but they come from opposite places.

The tell is what surrounds the failure. Under deliberate RTF, the failure was anticipated: spares are stocked, a replacement procedure exists, and the downtime fits in a window you can absorb. Under reactive maintenance, the failure catches you flat, no spare, no plan, overtime to source a part, and often collateral damage to connected equipment. The U.S. Department of Energy describes reactive maintenance as running equipment "until it breaks" with "no actions or efforts taken to maintain the equipment as the designer originally intended," and warns it carries the highest cost of any strategy. Deliberate RTF avoids that trap by choosing which failures to accept.

The breakdown can look the same either way. Deliberate run-to-failure surrounds the failure with a decision, spares, and a plan; reactive breakdown maintenance is the same failure with none of that.

When does run-to-failure make sense?

Run-to-failure makes sense when the cost and consequence of a failure are low and preventing it would cost more than it saves. Assets that fit share a recognizable profile. The more of these boxes an asset checks, the stronger the case for RTF:

Low criticality. Failure does not stop production, threaten safety, or breach quality, food-safety, or environmental limits.
Redundancy. A backup unit or an installed spare carries the load the instant the asset fails, so nobody upstream or downstream notices.
Low replacement cost. The part is cheap and quick to swap, so preventive labor would cost more than the occasional failure.
Unpredictable, random failure. The asset shows no warning and no wear-out age, so neither time-based nor condition-based maintenance can predict the failure anyway, preventive effort buys nothing.
Fast, contained repair. Fixing it is quick, needs no specialist, and causes no collateral damage to connected equipment.

Classic industrial fits include hallway and non-critical lighting, small in-line filters with a bypass, cheap sensors that fail to a safe state, hand tools, and redundant pumps where a standby auto-starts. For these, spending inspection and PM hours is pure waste. Sorting your assets this way is what an equipment criticality analysis is for, and it is the honest starting point for choosing any maintenance strategy.

Low-consequence assets are RTF candidates regardless of predictability. High-consequence assets earn prevention: predictive where failure gives warning, redesign or redundancy where it does not.

When is run-to-failure a bad idea?

Run-to-failure is the wrong choice whenever a failure is unsafe, expensive, or production-stopping, and it is dangerous when it happens by default instead of by decision. If a bearing failure can wreck a shaft, a seal failure can spill product, or a motor failure can idle a whole line, the failure cost dwarfs any PM savings and RTF is simply the wrong tool.

The more common failure mode is silent, accidental RTF: assets nobody chose to run to failure but nobody maintains either, so they quietly pile up as risk until one breaks at the worst possible time. That is not a strategy, it is deferred maintenance risk wearing a strategy's name. The fix is not to maintain everything, it is to make the RTF decision explicit for each asset so the failures you accept are the ones you actually chose. Assets running past their design life, single points of failure, and anything tied to safety or regulatory limits should be pulled out of the accidental-RTF bucket first.

How do you set up a run-to-failure strategy?

A real RTF strategy is a decision you can defend, not an absence of one. Setting it up asset by asset takes five steps:

Rank the asset's criticality. Score the consequence of failure on safety, production, quality, and cost. Only low-consequence assets are RTF candidates; high-consequence assets go to preventive or predictive strategies.
Weigh prevention cost against failure cost. Compare what preventive or predictive maintenance would cost over a year against the expected cost of letting the asset fail. If prevention costs more than the failures it avoids, RTF wins on the math.
Check the failure pattern. Confirm the asset fails randomly with no useful warning or wear-out age. If it degrades predictably, condition-based maintenance may beat RTF; if it fails randomly and cheaply, RTF is right.
Prepare for the failure you chose. Stock the spare, write the replacement procedure, and confirm the repair fits an absorbable window. This is the step that separates deliberate RTF from reactive breakdown.
Record the decision and review it. Log which assets are on RTF and why, then revisit when conditions change, a redundant pump that loses its backup, or a cheap part whose failures start causing collateral damage, no longer qualifies.

Those last two steps are where most programs fall down. An RTF decision that lives only in one planner's head is indistinguishable from neglect the day that planner retires. Recording it in your maintenance strategy assignments, alongside the criticality score and the spares plan, keeps it a defensible choice.

What does run-to-failure cost?

Run-to-failure is the cheapest strategy for the right assets and the most expensive for the wrong ones. The numbers that frame the decision:

The U.S. Department of Energy's O&M Best Practices guidance reports that a preventive maintenance program yields an estimated 12–18% cost savings over a reactive (run-to-failure) program for assets that warrant it, and that adding predictive maintenance saves a further 8–12%.
The same guidance benchmarks a healthy maintenance mix at roughly reactive 10–15%, preventive 25–35%, and predictive 30–40% of maintenance work, note that a well-run plant still runs a slice of assets to failure on purpose. Zero percent RTF is usually over-maintenance.
Reactive failures on critical assets carry hidden costs the DOE flags: overtime labor, expedited parts, larger spares inventory, and secondary damage to connected equipment, the exact costs deliberate RTF avoids by only accepting cheap, contained failures.

A reactive-heavy plant fails by surprise; a healthy plant leads with prevention and still runs a deliberate 10 to 15 percent slice of low-criticality assets to failure on purpose.

The takeaway from the benchmark is subtle but important: the goal is not to drive run-to-failure to zero. A plant with no RTF is spending PM hours on light bulbs. The goal is to make sure every asset on RTF earned its place there.

Where does RTF fit among maintenance strategies?

Run-to-failure is one of the four core maintenance strategies alongside preventive (time-based) predictive and condition-based maintenance. The mature move is not to pick one strategy for the whole plant but to assign the right strategy to each asset based on its criticality and failure behavior. RTF is the correct answer for the bottom slice, and a plant that never uses it is wasting money.

What makes RTF safe is visibility. When every asset's strategy assignment, criticality score, spares status, and failure history live in one searchable system, the difference between a chosen RTF asset and a neglected one is obvious, and an accidental drift toward reactive maintenance shows up before it hurts. That shift from decisions trapped in one head to shared, searchable records is exactly what the team in our CLS case study built, and it is what keeps run-to-failure a deliberate contributor to equipment reliability instead of a slow slide into breakdowns (see how Harmony keeps floor records searchable).