About 7 years ago we started to introduce the concept of 8 Maintenance Types in the RCM training we deliver.
This was in response to my involvement in the evolving Whole of Life cost and management models throughout the infrastructure sectors of the UK at that time. (circa. 2003 - 2006 ish)
The results have been so impressive that this has become part of the story of RCM that we tell during the RCM 101 course, and is developed further with additional techniques and applications during the RCM Analyst training course.
Some of the things to come out of this over the years have amazed even me, and the impact tends to change depending on the application within each sector, company, or even asset.
One of these has been the total uselessness of commonly used metrics in most companies. Particularly the Planned vs Corrective work order graphs.
Another impact has been on the approach that many companies take to forecasting whole of life costs, change out dates, and for forecasting CAPEX spending way off into the future.
4 routine tasks within RCM
The 8 tasks of RCM started off as the standard 4 routine tasks that everyone learns in basic training. As a very rapid reminder these are below. (Note: Not 4 proactive tasks.. that is entirely another discussion)
Predictive Maintenance (PTIVE)
PTIVE tasks are activities to detect whether failure is occurring or is starting to occur. It relies on the detection of a potential failure via some a vast array of approaches.
Once the indications of failure have been noted the goal of PTIVE tasks is to Predict whether the asset will still be performing satisfactorily when they return for the next inspection.
Preventive Tasks (PRES & PREP)
Within RCM there are two preventive tasks, Preventive Restoration (PRES) and Preventive Replacement (PREP).
To save time I am not going to go into the details of each here. But the goal of both is to act before failure occurs with a view to preventing the failure.
The last of the routine tasks. Often confused with PTIVE tasks, even to the point of being confused within standards that are published and circulating in the reliability community.
DTIVE tasks are activities to detect whether an asset has failed, not to detect whether it is failing.
They are applied based on tolerable levels of risk and are one of the rapidly evolving areas both of RCM and of asset management in general.
The Corrective Tasks
One of the natural occurrences of PTIVE maintenance is that sooner or later you will detect the onset of the failure the task has been created to manage.This task is known as the PTED task. it is a corrective task because it's entire goal is to correct the developing failure condition that has been noted.
However, unlike common views of corrective maintenance PTED tasks are planned tasks.
Why? Because we have taken a conscious decision to manage it this way.
We took a decision to implement PTED maintenance in the knowledge that one day the failure would occur, and that we would have the time to act to avoid or minimise the consequences of failure.
The same could be said for DTIVE maintenance. At some point, probably sooner than with PTIVE we will find an asset that has failed.
This is also corrective because we are taking action to correct a noted failure. But it remains planned because we took a conscious decision to manage it this way.
The last corrective task in RCM is that of Run to Failure or RTF. Run to failure seems to be very misunderstood by many in the industry, but I am confident that once understood it becomes a valid and useful part of any Asset Management Plan.
When we include Reactive Maintenance, because these still may occur, we have a very clear picture of the 8 tasks of RCM.
| Routine Tasks | Corrective Tasks | Reactive Tasks |
|---|---|---|
PTIVE Tasks - A task to predict whether the asset will still be functioning acceptably by the next inspection interval.
|
PTED (Predicted Tasks) - A task to correct the onset of failures observed during PTIVE tasks
|
None
|
PRES Tasks - A task to restore the assets prior to it's failure.
|
None
|
None
|
PREP Tasks - A task to replace an asset prior to failure.
|
None
|
None
|
DTIVE Tasks - A task to detect whether an asset has failed.
|
DTED (Detected Tasks) - A task to correct failures noted during DTIVE tasks
|
None
|
RTF
|
RTF - Run To failure. A decision to allow an asset to run to failure
|
None
|
None
|
None
|
ReactiveTasks-Tasks that need to be undertaken because of unanticipated and unplanned failures
|
This post is meant to be an overview only. We provide full training in RCM 101 and The RCM Analyst training.
But when companies develop a strong understanding of these 8 tasks, and integrate them into their data capture and asset management philosophies, it has a transformative impact.
In particular on the development of high confidence Asset Management Plans, covering both Operational and Capital Maintenance activities. The development of accurate Whole-of-Life or lifecycle plans, and the development of Risk Distributed Budget plans.
It adjusts totally the organisations view of corrective maintenance and the value of it, and it rightly sets up the expectation that Reactive Maintenance should largely become a thing of the past!
This is far beyond manipulating data in some spreadsheet. it is a living plan that improves in value in the course of doing maintenance.
I hope this was of use and interest, please share any impressions or comments with us in the comments section.