Reliability Centred Maintenance has a reputation problem. Too many people have experienced it as months of workshops producing a spreadsheet nobody opens again. That is not RCM failing. That is RCM done without a decision engine on the back end.
The concept at the heart of RCM, straight from the Nowlan and Heap lineage, is that maintenance must be justified by consequence, not habit. For each failure mode: what happens if it fails, and is there a task that is both technically feasible and worth doing? If the answer is no, run to failure is not negligence. It is the correct engineering decision, made deliberately and on the record. Commercial aviation learned this decades ago: a large share of aircraft maintenance is conditional inspection rather than fixed-interval overhaul, because redundancy and failure characteristics make that the rational choice. The industry that takes failure most seriously does the least ritual maintenance.
The Decisions Inside the Framework
- Task selection follows failure behaviour. Age-based replacement suits genuine wear-out; condition-based tasks suit failures with a usable P-F interval; failure-finding tasks address hidden failures in protective devices that reveal themselves only when called upon. One size does not fit all, a theme the podcast episode One Size Fits All, or Not takes on directly.
- The worth-doing test is arithmetic, not opinion. A cost-benefit ratio computed per task from your failure models and consequence costs, following the MIL-STD-2173 approach, turns workshop debate into numbers. Ratio below one: the maintenance program pays for itself. Ratio above one: you may be spending more to prevent the failure than the failure would cost.
- RCM and RCA are complementary, not rivals. RCM prevents the failures you can foresee; root cause analysis and defect elimination deal with the ones that arrive anyway, and feed the lessons back. The podcast episode Root Cause Analysis and Defect Elimination maps the boundary between them.
How the Tools Help You Discover the Benefit
The RCMCost module of Availability Workbench operates as a hybrid of RCM and FMEA methodology: functional location hierarchies, functional failures and causes represented visually, failure models and consequences attached to each cause, and the cost-benefit ratio calculated per task. Analyses integrate with AvSim, so the strategy the RCM study recommends can be tested at system level in simulation before anyone changes a work order. Functional failure data imports from spreadsheets and CMMS extracts through table matching, so the study starts from your real hierarchy rather than a retyped one; see our article on CMMS integration for how far that pipeline goes.
The benefit you discover: somewhere in your PM schedule you are almost certainly polishing equipment that would be cheaper to let run, and somewhere else a critical failure mode has no task against it at all. RCM with numbers finds both, which is precisely the bottleneck-first mindset our white paper Working on the Right Things argues for. Our RCM service and RCM training course cover the method end to end.
Go Deeper
- Software: RCMCost, RWB FMEA/FMECA, AWB Availability Simulation
- Services: Reliability Centered Maintenance, FMEA/FMECA, Maintenance Planning and Scheduling Uplift
- White papers: Working on the Right Things, Getting Maintenance Right, Setting Expectations
- Podcasts: One Size Fits All, or Not, Root Cause Analysis and Defect Elimination
- Next in the series: The P-F Interval and Asset Criticality
How can we help? Talk to us at contact@mantua.group.