Yes I can wait. My appreciation for sharing the info. Of course confidentiality is necessary. TQ

Hullo Josh,

Your question to Daryl implies that as we improve costs will go up. If you do the RCM on the right systems properly, implement its results, you will find that costs go DOWN while availability goes UP. Always assuming that compliance is over 90% and quality of maintenance work is good.

V.Narayan

Dear Vee,
What I mean is that as the amount of PM works & its costs go up with time, the amount of CM&BM works and their costs go down. I wish I can sketch a graph of cost versus time here but cannot be done in this forum. The two lines of PM & CM will meet, giving the minimum total maintenance costs (which equals the sum of PM costs + CM costs).

On the LHS of this min point, the total maint costs go down with time but on the RHS, the total maint costs go up because of presumably too much PM works ie excessive.

Also pls note at the min total maint costs, the amount of PM over CM is at 50%PM:50%CM split. Above this ratio, which we are encouraged to achieve is the magic figure of 70%PM to 30%CM (by cost as the common denominator). Of course as you said as we strive to achieve this 70%PM:30%CM, we should aim for 90% PM work schedule compliance as well as keep improving the effectiveness of the PM work tasklist to ever better detect/identify equipment problems or deteriorations as early as possible (before these result in functional failures or breakdowns causing production or HSE losses).

You also state that the system availability will improve as the amount of PM work go up. Ah... this is the statement that I intend to clarify further ie whether this does really happen in reality. Any case histories to substantiate this statement? I think Daryl said it's dependent on situations or industries.

Anyway, my intention is just to doublecheck this matter as we really embark on the journey. "To begin with the end in mind" as Covey said it.

Appreciate valuable inputs. TQ

Jo's_total_maint_cost.ppt (42 Kb, 11 downloads)

Dear Josh,

This is simply untrue on many levels:

1) The cost of PM is not necesarily going to go up over time

2) There is no generic best mix for PM / CM. It depends on the configuration of the assets within each particular plant. Anyone telling you different does not understand the dynamics of RCM.

3) There is no WAY that you should aim for 90% PM under any circumstances. (Given that you are actually referring to routine maintenance activities here) Again the configuration of the plant, the level of risk a company is willing to accept and the equipment profile of the plant will have a lot to do with how this will pan out.

4) Will costs necesarily go down? No. They are unlikely to rise, but they may not actually fall either. Cost effectiveness is the goal here, not merely cost reduction. This is 1980's thinking and is out of date.

5) Will availability necesarily go up? No. You could be commencing a study whereby availability is already at a high level and it was due to another issue, or a more proactive management approach, that initiated the RCM effort. The whole "bad actors" / wait for a problem to arise, attitude is also outdated thinking I believe.

Hope this assists.

Daryl Mather
www.strategic-advantages.com

Hullo Josh,

There is a school of thought that belives strongly in what you have stated as hoping to prove - there are a couple of books about it as well.

I dont believe in this school of thought. In nearly 40 years in a variety of Industries, I have never been able to get this correlation. In fact, I have found that
- If you do e.g., RCM on the right systems
- Implement the RCM results properly
- Ensure that W.O. compliance is >90%
- Ensure work quality (both Ops and maint) is good
- Develop a culture that that does not accept failure, e.g., by proper RCA, not superficial ones.

Then, PM and CM volume reduces, cost reduce and Availability goes up. But keeping compliance and work quality high requires sustained effort, and often we fail to do this. Hence all the so called 'RCM failures'.

I agree with Daryl's comments, there is no simple unique answer to your points. There are a variety of things influencing maintenance results, it is not a simple mathematical equation. But if you do the right things in the right order, you will win in the end.

V.Narayan.

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

Josh,

One other point about your cost optimisation curve. While the principle is probably OK, people cannot possibly play around with their maintenance regimes to get data points for these (what I call mythical) curves.

However, the important issue is that if the curve is true, it is pretty flat near the optimum point. This raises some serious decision criteria.
- If the curve is flat, a wide range of PM to CM/BM options will produce substantially similar costs. So the actual ratio of PM to CM/BM is not critical at all, and any set of maintenance regimes should produce similar costs. So much for the optimisers!
- Availability on the other hand starts going up from about this 'optimum' point as we increase PM, and then starts dropping off as PMs increase planned downtimes excessively. The availability curve looks like an upside down bathtub, but shifted to the right.

So the true optimum is some point to the right of the cost optimum point, assuming the availability is worth something to you.

I dont know if I have made this clear, but I will be happy to discuss this with you outside the forum. Regards.

V.Narayan.

It appears there is people getting this kind scenario as per this maint scorecard:
http://www.maintenancebenchmarking.com/best_practice_maintenance.htm.
It would be interesting to see their actual KPI values achieved in reality. TQ