R&M Measurable.

  • Thread starter matthew evans - 2002
  • Start date

matthew evans - 2002

Hi everyone!

It's been some time since I last posted a question on the forum but I have a real brainteaser for everyone.

During our last surviellance visit from our accreditation body (LRQA) we had an observation raised concerning a measurable for Reliability and Maintainability.(R&M)

My problem is that we manufacture one off machines so we don't get constant R&M data for a repetative process. I have investigated producing a measurable for availability of machinery but our customer target of 97% almost impossible to reach in a reasonable time scale. We could probably reach it within 2-3 years.

I have also considered a measure of Mean Time Between Failure (MTTR) but we get so little feedback that it would be difficult to plot any sort of reliable graph.

How does everyone else deal with this problem?
Any help would be appreciated.

Laura M

I worked with a one-off T/E company. They had customers requiring T/E, and put on a Customer Service person to contact, collect and report on R&M data. They were highly customer focussed, and when they sent people on warranty calls, they made a point of talking to maintenance personnel about what they may have fixed without the warranty call. Customers were interested in recording downtime, so that number was easy to come by.

They also used internal run-offs to get estimates of MTBF.

I don't know if it would work for you, but they were successful in developing the relationship with their customer to obtain data. And they didn't collect it for ISO - it was a part of their overall strategy to develop strong relationships with the customer.

Michael - 2009

R&M Reliability

For GM I did a reliability study that used the BOM of the equipment we manufactured. With the help of service personnel and service records and people who have been in the field, we went over the BOM (mechanical and controls). We examined every item/detail and determined which were critical components. When in doubt we included the item/detail.

Then we did research on the critical components. We used our vendors for the purchased parts. They supplied almost all of the MTTF/life expectancy. If they could not supply the MTTR (usually not) we discussed it among our service/management team or did a quick field measurement. With this information we were able to plug the numbers into the formula for availability/uptime (what GM wanted). The formulas are in the reference pages of the R&M Guidelines (SAE) book.

In addition to that we did a Capability study (CpK) and the required sound/vibration/lubrication/etc. studies. GM was happy with it. If you are building similar one offs, you could easily create a data base with an increasingly larger MTTF/MTTR spreadsheet. It gets easier after a while because the number of components for which you have to research should decrease.


Thanks for the thread. I am just starting down the R&M road with Ford for Q1..and the MMMF and MTTR data they require seems daunting.....any experience with the FRED software that they require?


Training yes! -- experience using the software no!
The ability of the software is quite extensive, and overall system availability is pretty easy to establish, but the 2nd and 3rd level data is harder to realize.
I am still new to this also, and I believe the accumulating of failure data to use in these programs, in order to generate a FRED report will be difficult.
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