In recent years, the maintenance and reliability community has given well-deserved attention to PM Optimization (PMO), with several contributions from Reliable’s great writers included. Plants everywhere are uncovering hundreds of wasteful Preventive Maintenance tasks, tasks that consume craft labor, generate frustration, and crowd out the meaningful work of identifying and eliminating failure modes on the assets that matter most.
But while PM waste has been getting its moment in the spotlight, its quieter twin has not: wasteful Predictive Maintenance (PdM) tasks.
Wasteful tasks don’t appear by accident; they appear when no one owns the strategy.
Both PM and PdM waste stem from the same root cause: the absence of ownership, governance, and discipline in how maintenance strategies are created, modified, and protected. This article is not just about identifying waste. It’s about understanding where that waste comes from, why it accumulates, and what plants can do to remove it and, very importantly, prevent it from ever creeping back in.
Wasteful PM and PdM: Two Sides of the Same Problem
Most leaders are familiar with PM waste:
- PMs added decades ago that no longer apply
- OEM checklists blindly loaded into CMMS systems
- “One-time” fixes that somehow became annual PMs
- Redundant tasks created during leadership turnover
- PMs added as a reflex after a single unusual event
But PdM waste is equally common and often more expensive:
- Applying vibration, ultrasound, thermal, or oil analysis to non-critical assets
- Increasing PdM frequency because “something happened once.”
- Reducing PdM frequency simply to reduce costs without thought of the frequency needed
- Running PdM routes for years without a single meaningful finding
- Collecting far more data than anyone has time to interpret
- Adding sensors because the tool exists, not because the failure mode demands it
Both types of waste erode reliability, dilute crew capacity, and frustrate teams.
The Hard Reality: PM/PdM Optimization Is One of the Most Labor-Intensive Efforts in Maintenance
There is a misconception that PM Optimization is a quick cleanup activity. Anyone who has actually lived it knows better. A proper PM/PdM Optimization, especially in a system that has drifted for years, is a massive undertaking.
I led one optimization effort that required eight full weeks:
- Multiple engineers and planners
- Production participation
- A dedicated reliability resource
- Craft input and validation
- A detailed review of every PM and PdM task, one by one
Eight weeks fully dedicated to optimization. Not implementation. Not training. Just the cleanup itself.
When you’ve gone through that kind of effort, it changes how you see the system. You understand why protecting the CMMS from waste is every bit as important as removing the waste that’s already there.
Both forms of waste, what’s already in the system and what gets added back into the system post PMO, are equally dangerous. Effective reliability work requires two disciplines:
- removing the waste that clogs the CMMS today, and
- protecting the system so waste cannot creep back in after optimization.
Where All This Waste Comes From
- The “Something Happened” Reflex
After a failure or anomaly: “Add a PM so this never happens again” or “Increase the PdM frequency.” Without RCA or FMEA, this becomes the easiest way to show action, even if the task has little value. - No Living Failure-Mode Library
Without a standard failure-mode library, teams end up inventing new tasks for the same problem over and over again. - OEM Manuals Treated as “THE” Strategy
OEM manuals are designed for ideal environments, not your plant. Copy/paste creates an unnecessary burden, and OEMs don’t know your operational conditions. - Well-Meaning Over-Engineering
New leaders often enthusiastically take on tasks, especially PdM tasks, because technology feels like progress. - Audit and EHS Additions
“Add a PM to cover this” becomes the go-to response for findings, even when a PM or PdM doesn’t even cover the failure mode. - Production/Maintenance Misalignment
If no one agrees on who owns PMs and PdMs, both sides add tasks defensively, and no one confidently removes work.
Who Really Owns PM and PdM?
Production owns the assets.
Maintenance owns the capability of the assets.
When this relationship is respected, reliability systems thrive. When it’s ignored, both PM and PdM systems become chaotic and misaligned.
Production must lead the PM/PdM Add–Change–Remove process. Maintenance & Reliability supports and guides.
The PM/PdM Change Review Board: Your System’s Gatekeeper
Board Members:
- Production Leader (Chair)
- Operations Representative
- Maintenance Leader
- Reliability Engineer
- EHS (as needed)
No task is added, changed, or removed without answering:
- What failure mode does this address?
- What is the asset’s criticality?
- What is the right strategy?
- What is the cost vs. benefit?
- How will we measure effectiveness?
- Does this duplicate or cover failure modes that already have existing PMs or PdMs?
If a task cannot be tied to a defined failure mode and criticality ranking, it should not enter the CMMS. Run-to-Failure (RTF) Is Not Neglect; it’s Discipline. RTF is a mature strategy for low-criticality assets. Protecting RTF protects PdM programs from overload of labor & costs as well as frees maintenance crews to focus on what really matters. Once there is alignment on the Board regarding any changes, the CMMS can be modified.
A Vision of a Disciplined PM/PdM System
Imagine a plant where:
- Every task exists for a specific reason
- Production leads the strategy
- Maintenance ensures capability
- PM & PdM are applied only where meaningful
- Run-to-failure is respected
- Craftspeople trust the workload
- Leaders trust the data
- Waste is removed … and kept out
Protecting the System Is Stewardship
Removing waste is essential. Protecting the CMMS from new waste is equally crucial. Both are acts of stewardship for assets, craft labor, and production capability.
This is what the foundation of world-class reliability is built on.
