Ramesh Gulati of ATA sent this in response:

Maintenance Work Classifications:

Maintenance can be classified in four major categories:

1. Preventive Maintenance (PM)
2. Predictive Maintenance (PdM) aka Condition Based Maintenance (CBM)
3. Corrective Maintenance (CM)
4. Capital Projects –Maintenance (CPM)

Maint. Work 1,2, and 4 have been defined and all of us understand it. However, corrective maintenance creates lot of confusion.

3. Corrective Maintenance (CM):
Asset repair resulting from PM & PdM actions or breakdown/failures.

Corrective Maintenance is repair of asset to bring it back to it's designed or an acceptable condition.


The CM work can be further classified in three:

a) CM – Scheduled :

The repair work discovered as a result of PM or PdM actions. This work should be or can be planned and scheduled.

b) CM - Run –to-Maintenance (RTM) :

If we have performed FMEA/RCM analysis on a specific asset/component and made decision to not to perform any PM/PdM but to let it run –to –maintenance (failure) because it's a cost effective strategy, then we will call this as CM-RTM. It's not a negative. This failure is by design. This is not a critical asset and should be repaired in scheduled manner.

( Water cooler, circuit board, electrical component, or a line replaceable unit etc. )

c) CM – Unscheduled (Run-to-Failure) :
aka failure repair = breakdown maintenance = reactive maintenance

This CM is failure or breakdown work. It's fixing of the asset after they fail. This work is also known as reactive. Most of the time this work will break the regular schedule to get it done.

Usually we have found that there is a big confusion when we try to mix maintenance work with how we respond to get it done e.g. Emergency work is really CM-Unscheduled or reactive which needed to be done now. In some organizations, breakdown work is called urgent maintenance but could be done within 48 hours.

Roger Harris sent this response:

As a Maintenance Manager in a large automotive manufacturing plant, I faced this same problem and answered it by creating a new work type called PMO for PM Originated work. This did two things for our organization:

1) It allowed us to measure the effectiveness of our PM system by determining what percentage of our repairs were driven by the most qualified individuals (Maintenance Crafts Personnel) and;
2) Created a category of work management costs that could be directly compared to the cost of running to failure by considering downtime, cost of quality, and the added cost of repair that would be incurred by affecting other components or systems.

This requires the PM focus to be one of; clean, lubricate, and inspect, and allows for better scheduling of PM tasks by forecasting accurate equipment downtime associated to the PM routine.

This helps maintain the relationship with the equipment stakeholders by only having it down the time that you requested and agreed to as much as possible, and allows the mechanics to complete their scheduled work by not bogging them down into lengthy repairs.

This will help the entire organization see that the PM efforts are manageable and supportive of changing the culture from reactive to proactive.

This is also a mandatory mind set shift if you ever expect to reach the best in class goal for scheduling accuracy of 95%.

By closing the PM work order and creating a new PMO workorder the parts needed to repair could be ordered against this work type which separates the cost of repair and PM and properly identifies it as PM originated expenses. Not only does this accurately identifies cost it improves equipment downtime when it is possible to return the equipment to service and wait on the arrival of spares with the equipment running. Any good EAMS/CMMS software support consultant can help you configure your system to support this process. If your software or consultant is not capable, find a new one, otherwise you will never reach the full potential of your groups human capital, or clearly identify for management the true value of being proactive through preventive measures. Mr. Smiths points are accurate and valid, but there are solutions for these problems.

Roger Harris CMRP CPMM
Senior Business Consultant
Total Resource Management
MAXIMO & LAWSON Consultants
Cell: (502)664-7089

One more reply came from Jeff Wahl:

I saw your Preventive Maintenance Tip in the Maintenance-Tips from Reliabilityweb newsletter today. You gave definitions for PM and CM. I have to ask if CM should be sub-divided into two categories, such as CMP and CMU. P and U divide the category into Planned and Unplanned Corrective Maintenance.


When a PM exposes CM work that needs performed, it shouldn't be in the same bucket as a CM that is initiated during operations, say. CMP could also be categorized as a PMC if that makes more sense.


Sincerely,
Jeff Wahl

Hi Terrence,
You have created some good discussion here and I appreciate your concerns. Reading the replies of the group I find that there is need to go further into the discussion. What is the reason for trying to determine is work Corrective or Preventive? If the mission is to understand reliability performance one must consider anything that is performed to restore the equipment to acceptable design capacity as corrective. I say this because I view the corrective measure as a weakness in the reliability of the equipment and may indicate more tend and adjust is needed to operate. Measuring corrective this way will allow you to compare like type assets to determine which models have the lowest operating costs over the life of the asset. This will also support the purchasing department with information to make better purchasing decisions.
Similarly, I feel that understanding the maintenance department's proactive and reactive tendencies is a vital part of managing the maintenance department. So I view corrective planned maintenance as part of the planned maintenance program and view it as proactive in nature. Unplanned Corrective Work is viewed as a negative impact on both the reliability of the equipment and the operational efficiency and effectiveness of the maintenance department. Unplanned corrective work should be avoided unless otherwise planned for by identifying run to failure equipment. My question is what are you trying to understand by measuring corrective work routines? Maintenance Operational Performance, or Equipment Reliability scores? They are both part of the overall continuous improvement process and require specific training and EAMS/CMMS configuration planning. Getting at a clear understanding of these two issues are normally when I see the confusion mount about what is corrective maintenance. Thanks for starting this great discussion.
Kind Regards,
Roger Harris CMRP CPMM

Sorry, if my question does not related to this topic. I've some only one question, how different Corrective maintenance and Reactive maintenance?

Is it alright to tell technicians to raise a separate/sub/child/follow up work order for rectifying major defects found during PM, which require another planning and scheduling process but to rectify minor defects found during PM on the spot under the same work order, if possible to avoid unncessary hassles, delays or logistical problems?

This message has been edited. Last edited by: Josh,

Jeff, what does PMC stand for?

Ramesh, you have divided CM into 3 categories? Have you got actual results? What's the percentage breakdown like?

Roger, what percentage of PMO (PM Originated work) do you get? Any target percentage for PMO?

Panuphan,

For me, reactive maintenance covers corrective maintenance and unplanned breakdown maintenance (the extreme form of corrective maintenance) while planned maintenance covers planned preventive maintenance (PPM), planned run to failure (RTF) from maintenance strategy, corrective/preventive maintenance found during PPM, inspection works and plant changes/modifications.

I think splitting CM work orders further into categories with a result of having more administrative work can only be useful if you have defined a set of KPI's or reporting feature to monitor and improve ON.

I am curios how KPI's / reporting is done by the forum members who uses this split up. Maybe they can post some example?

Hi Josh,
The PMO catagory does not have a fixed target that is established to my knowledge. I used it in an automotive company that had more than 70% of it's man hours worked against reactive work types such as breakdown (CM), emergency (EM) The remainder of time was spent on projects and PM. PM was less than 5% of our time when we started trying to become more proactive. It (PM)represented 35% of all work orders and 5% of man hours. This was screaming to me that the PM work routines were not effective since we were still posting over 70% of our man hours to reactive work types. The first time we measured PMO it was less than .001% It took over 6 months to drive the number up to .02% because we were working on changing work attitudes and supervisor involvement. When I left that company a year ago we were running at 6% on PMO work types. The reactive work was a little under 30% when measured in man hours. This was a major improvement in our facility and the focus was on the trend more so than the actual number. This entire process occured over a 3 year period. I hope this helps.
Kind Regards,
Roger Harris CMRP CPMM

Josh,
I was only giving examples of what I saw as useful splits in the CM category.
CMP= CM Planned
CMU= CM Unplanned
or another possible type
PMC= PM Corrective= the PM follow-up work that isn't part of the job plan and must be planned such as you mentioned. PMC could be lumped into CMP if preferred.

It would be nice to know when a CM actually impacted production scheduling as opposed to a repair initiated by an operator's rounds or PM or whatever. I'm in a batch plant environment and there are many opportunities to correct equipment without impacting the production schedule.

As PdM repairs, operator rounds and pre-run checks are a valid part of maintenance, the CMMS system should be able to provide enough granularity to show that those repairs were discovered and made outside of the production schedule.

We don't have it where I am now, but I can see some usefulness in it.

J-

Roger, I guess everybody has to start somewhere. It's tough to convert those auto guys from Henry Ford's idea of " Don't fix it if it ain't broken".

What's CPMM, btw? Is it Certified Professional in Materials Management?

This message has been edited. Last edited by: Josh,

Wally, PMC = PM Corrective is understood now. Have you got any actual figure for this work type? What you don't have? CMMS or the operator rounds and pre-run checks in CMMS?

Hi Josh,
There are challenges in changing the culture in any organization. We were reactive because we didn't know how to be proactive. The biggest problem for our culture shift was knowing what to change to. You have asked the question of what percentage of PM Originated work should be and I suggested that the trend is the most important factor, this has its limits too. There is a standard that says for every 8 PM work orders you should see at least 1 corrective work order. The idea being that if you don't see at least one corrective for every 8 your PMs are not effective or you are PMing too much. Hope this helps.
Roger Harris CMRP CPMM

These are all excellent posts - on an excellent subject. However this subject can be somewhat large as books have been written. I'd like to add some quick thoughts.

Bullet points:
1. The purpose of planning can be many-fold but at end of the day, the generation of a weekly schedule should be a primary result. Note: 80% of all sites I've been too are unable to generate an automatic resource-leveled schedule from their CMMS/EAM product.
2. Proper categorization of that work - inside the CMMS/EAM product - is also important.
3. Some fields are more important than others (such a Worktype, Workorder Priority, Asset priority, and job Status).
4. But if your maintenance backlog is not accurate there might be some data ownership problems.
Some clients have a "gatekeeper" position which I have found to be very successful.
5. KPI's are a powerful management tool - and - they rely on accurate data in the database.
6. There can be many Worktype categories and definitions for each, but a key KPI is the ability to define (and measure) Reactive maintenance, as this is most significant and a telling measurement.

As a long-time CMMS/EAM consultant I've seen alot of system designs. Plus there are several correct answers to establishing an integrated P&S sysstem. Unfortunately not all sites have fully qualified Job Planners let alone schedulers. So ... you have to be creative.

And here is a sample litmus test for your system:
1. Do you have a WEEKLY SCHEDULE process in place?
2. Are you able to extract weekly compliance analysis?
3. Is your backlog >90% planned at any given moment
4. Can you measure Reactive maintenance?
5. Do you have a strategy for "moving away from reactive maintenance"?

I haven't written a book, but I do have a white paper published by Maintenance Tecnology, March 2006, on the The Elusive Weekly Schedule.

thanks for letting me post.

w/br
john reeve
Synterprise Solutions
423 267 5363 - office

Follow up maintenance from a PM observation or procedure is the return on our PM investment.

Any extra corrective activity that is not part of the preventive maintenance strategy or procedure, but a result of it must be captured on a separate work order and coded as such. Additionally, it is a proactive activity and the work order should be deemed as such. In a lean maintenance environment, follow up corrective work from PM's should amount to 12% to 20% of the PM total. This is your payback for performing the PM's.

This is essential for an efficient Work Management system. The work management system is the backbone of any Reliability and Lean Maintenance Program. All work activity must get recorded and properly coded into different categories for performance, financial and root cause analysis. There should be only five to ten major work codes falling into the categories of Proactive, Reactive and Other. This should not be confused with problem codes. Work data that gets recorded, measured and analyzed gets continuously improved.

In conclusion from the data analysis, If data shows large amounts of corrective work resulting from PM's or emergency work activity on PM'd equipment then the PM frequency may need to be shortened. Hone your program until you reach the 12% to 20% Sweet Spot.

Provided by Leon Reed
Sr. Reliability Engineer, CMRP
Eli Lilly
Indianapolis IN

In addition to adjustment of PM frequency, the contents of the PM instructions must be re-evaluated and determine if additional check points may be added or instructions edited (specially in the equipment units on top of a Pareto analysis on number of corrective work orders arising from PM findings.

What is the opinion of a PM program that produces less than 12% of CM ?

Leon,

"Any extra corrective activity MUST be captured on a separate work order."

- I would say SHOULD instead of MUST. For major jobs, yes must be recorded in a new work order but for small/minor jobs, no need to do son because can just add another operations in the PM work order. This is for practicality purposes.

"Follow up work order should be between 12 to 20%."

- May we know how did you come up with this figure? Is this figure actual from your plant?