50 Failure Modes of Electric Motors

An associate of mine just forwarded a link to a great video on the 50 Failure Modes of electric motors. This is a great tutorial on the ways that motor's can fail and which of those failure modes can be controlled by our maintenance planning and how motor rebuilds are specified.

You can find the video here: http://www.uesystems.com/vids4htmls/fifty-failure-modes-of-electric-motors.aspx

Co-Gen Uptime Write Up for Gresham OR

There is a nice write-up in Triple Pundit about the success that Gresham Oregon is having with their Co-Generation operation, which provides 55-60% of their operating energy requirements.

While it isn't mentioned in the article, the Co-Gen system was the focus of the first Reliability Centered Maintenance (RCM) study that Veolia Water conducted. Using the maintenance approach's developed, Veolia Water has maintained uptimes that exceeded expectations and has helped to achieve the power output that has them on their way to a sustainable wastewater treatment plant.

Congratulations to the Veolia Water Gresham Team and the City of Gresham!

http://www.triplepundit.com/2011/12/oregon-model-sustainable-cities-aint-portland/

Root-Cause Analysis and FMEA Similarities

It sometimes seems that there are competing "tools" used to improve reliability of equipment. Pickup any of the industry magazines the there is always a presentation of one "new" technique or another: Reliability Centered Maintenance (RCM), Failure Modes and Effects Analysis (FMEA), Root-Cause Analysis (RCA), and others. I have seen similarities between many of these tools, but a recent free webinar put on by Think Reliability did an excellent job of showing how RCA and FMEA are very closely related and support each other.

You can find the video here: http://www.thinkreliability.com/video/2009-10-13-RCA-FMEA/2009-10-13-RCA-FMEA.html

Reliability Centered Maintenance and a Motor System

If you are ready to jump into some real "meat and potatoes" on motor systems and Reliability-Centered Maintenance (RCM), I found a great video that combines them both. The presenter has written on motors and their maintenance extensively. In this short presentation, he focuses on how a motor is part of a system, demonstrates how to calculate the reliability of the system, and then looks at strategies to improve reliability using RCM.

http://www.motordoc.com/Presentations/TTFE/TTFE.html (Please allow a few minutes for download)



This video is heavy on content, but I would recommend watching for the higher level principals and consider how these might fit into or improve your program. Pay particular attention to the reliability calculations of redundant assets, which is a real eye-opener.

Robust Design for Systems or Processes

A key to recent success in the manufacturing industry has been the application of Robust Design or Taguchi Method. While the details of the process get deeply into statistical mathmatics, the concepts are quit simple.




This diagram demonstrates the key relationships between any process or system and its environment. The "signal factors" are the inputs into the system, this may include a product at a certain stage in a process and then there is the "response" which is the condition of the product after it has been through the process or system. For this "black box" there are also system inputs which includes "noise", things that can't be controlled, and "control Factors" things which can be controlled.

As system operators, we operate many systems where we attempt to control the process or system with our control factors. The lesson that we learn from Robust Design process is that these control factors often have a complex and difficult relationships. Many times we attempt to control a process or system response by varying certain control factors and ignoring others, without any understanding of how these processes relate to each other. Robust Design when applied allow you to determine the "Control Factors" which have the most leverage in the control relationship.

Incidentally, these "Control Factors" would make great Key Performance Indicators (KPI)'s for controlling your process or system.

Robust Design is not often discussed in the context of Asset Management, however, using the statistical strategies to evaluate failure data could be very beneficial in determining techniques that will allow significant extension of life.

System Level MTBF's Expected vs. Actual: Are you achieving your RCM ROI?

Today I came across an interesting article on calculating MTBF's for a primary function of a system. The article provides details about how to calculate an MTBF, however, the most interesting point was that you can use MTBF's to evaluate your RCM based expected MTBF vs. the actual MTBF you are experiencing from your CMMS data.

The author doesn't mention this point, but I believe that every time there is a Corrective Maintenance activity, particularly if it is unplanned and stops the Primary Function of a system, then the failure should trigger an investigation loop into:

1. ) Did the failure meet the desired MTBF
2.) If not, what was the root-cause of the failure and does the RCM assessment or the PM activites need to be modified to achieve the desired MTBF.

The mathematical tools provided in this short article, will help anyone who has a system hierarchy with primary functions (see video: http://www.youtube.com/watch?v=nEGE69ie5QE) to evaluate and set-up their desired vs. actual evaluations. Check out the article at: http://physical-assets.blogspot.com/2008/05/this-article-is-adapted-from-my-new.html

Building a Zero Based Budget Using RCM Strategies

This morning I received and email with a link to a white-paper on building a budget using RCM strategies. I am familiar with the company. ARMS Reliability Engineers, LLC and have seen a demonstration of their software.

While I found their software to be extremely detailed (in a good way), the detail doesn't seem to offer much benefit for our industry because the water/wastewater industry has so much redundancy.

However, the outline laid out in the paper
is an excellent summary of the approach I would take to doing an RCM based budget:

1.) Develop a system/function based hierarchy
2.) Review/update the Asset Register
2.) Rank criticality (not clearly identified in the paper, but part of RCM)
3.) Do the RCM/FMEA
4.) Identify the tasks to do PM.
5.) Run a simulation on the reliability impact of those tasks (monte carlo)
6.) Select the lowest life-cycle cost approach
7.) Budget for maintenance (parts and labor), repair/replacement(RR), and capital.

The ARMS software makes step 5 easy once you can select the expected failure frequency for an asset, but without the sophisticated Monte Carlo analysis, you can pretty simply look at the cost and frequency of doing your maintenance actions and compare them with the change in expected life and RR costs to develop a more direct assessment of the value of doing certain actions. The RCM II book by John Moubray outlines several ways of evaluating the required frequencies for PM actions.

If you are considering changing your PM strategy to improve reliability, this paper provides a good strategy outline. You can find it at: http://www.reliability.com.au/dynamicdata/data/docs/zero%20based%20approach.pdf