Hi all,

I'm doing a report for a college couse. A long time ago I used to work with a lad who had been employed by DuPont. They had a formula, (or possibly formulae) for working out how much money a particular 'find' with VA or thermography etc. had saved them, as opposed to running it to failure.

But I can't for the life of me remember what it was.

Can anyone help me out please??

Thanks.

Most probably the formula you are trying to remember is related to the production losses due to the equipment not in operation. Then the formula is tied to the particular process at Dupont where the equipment is used.

In addition, your friend probably included savings in repair costs when comparing:
* acting now since he "found" the failure, vs
* how much would be the repair costs if the failure continued unnoticed until the equipment breaks down.

For example, if you have an air handling unit equiped with prefilters, filters, and HEPA filters. The HEPA filter price is much higher than the other two, in addition there are additional costs for HEPA filters certification. If you detect certain failure early you could eliminate them early with the replacement of the economical pre-filter. The longer time the failure gets unattended the larger probability of the damage migrates to the filter and the HEPA; therefore the repair would be replace additional parts, HEPA recertification, longer dowtime, larger labor costs, etc.

Yes Eugene, that's kind of the thing I mean, and like I say I'm not sure but I think they used normalised figures for repair-costs-if-left-to-failure.

My (bad) memory seems to think it was 30% of replacement cost for machines upto a certain power, and a different figure for bigger stuff. Not sure how they took production loss into it, but I suppos that is fairly easy to calculate on a case by case basis.