Fitness for Purpose; A negative philosophy, or required business driver?

Fitness for Purpose; A negative philosophy, or required business driver?

  • For

    Votes: 3 30.0%
  • Against

    Votes: 5 50.0%
  • Not sure?

    Votes: 2 20.0%

  • Total voters


I have been involved in ‘Quality’ since leaving secondary education as an inspector for a small precision engineering organisation manufacturing various safety valves for the nuclear, oil and gas industries.

I have been witness for many poor quality parts being delivered to our customers, under the pretence of ‘fit for use’ simply because they needed the part urgently. The part’s failures ranged from poor appearance to dimensional incorrectness. As an inspector trying to instil confidence in the company’s workmanship, this was detrimental to my goal.

I have since been promoted to quality manager where the fight to scrap what I consider the biggest misleading philosophy ever thought up, was taken up against the engineering manager/s etc. I often won the case, although several parts had been returned as unacceptable prior to my appointment and to me the damage had been done. It seems Fitness for purpose has become an excuse for people to manufacture parts at a lower level of quality, or to use cheaper materials and tooling.

I’m now involved with several organisations as a quality contractor and promoting my opinion is becoming far easier as my word is consider valid.

Okay, maybe ‘fitness for purpose’ cannot be defined as simply yes and no answers but if a part is physically incorrect, irrespective of the parts required use, it should be failed and at the very most sold to the customer as failed at a discount price!

What does everyone else think? :bonk:


M Greenaway


I think you are absolutely right (ive also done my fair share of inspection).

Any parts shipped that are not strictly to specification should be concessed under a deviation. Any concession that is 'permanent' should result in an engineering change.

The trouble with the scenario you descibe, and that I have also witnessed, is that the fitness for use is decided by someone who really doesnt understand the use of the product, but has rather used this as an excuse to ship anything.

I dont have a problem with someone with technical expertise deciding that departure from the engineering specification has no detriment to fitness for use, so long as it is documented.


Super Moderator
Not to get too far off topic, but thus sounds like the philosophy of the US Army towards its soldiers. Quality is a word between Aardvark and Zebra.

Sorry to wander off.

The phrase "fit for use" especially in the nuc industry is scary. This type of philosophy allows for too much individual interpretation and deviation from spec. "Fit for use" may work in "Jakes Garage" but not in industry where the smallest imperfection can lead to disaster.


Not sure speaking

I think how the phrase is used plays a dramatic part in the answer. If 'fit for use' is being used to justify deviation from specs, then shame on us. If the deviated spec is not that critical, that should have been pointed out ahead of time.

If it is part of the contract review process and the rules for its use are spelled out in advance, then it could actually help us.

I had a client whose customer had a really tight spec on a part. During the feasibility review, the client would routinely note that they could not process the quote because of the spec. The customer would always tell them to just get it a close as they can; 'fitness for use'. It still puzzles both of us. :eek:


Thanks for that, I thought I was on my own in the disapproval of fitness for use. I think that the comments above are great and I especially related to those stated with regards to the high specification/ tolerance instances. At the time, as stated, I was working in the Nuclear, oil and gas industry making safety valves with tolerances almost always with three decimal places (metric). In one instance I was asked to release a part that was being inserted into a nuclear reactor! It was 0.005m/m undersize on a diameter. I new it would fail thier inspection and in fact was detrimental to the safety of the reactor.

I was told to pass it because it was only just over and it would be fit for use! I looked at the man and dropped the whole valve on the floor there and then! There was no way it was getting through me!

The manager had to contact the customer to explain why he would not be receiving the valve. He was told in no uncertain terms that it would have failed anyway!

Don’t forget to vote!


E Wall

Just Me!
Trusted Information Resource

I think something to consider is equality...Not all products are equal. By this I mean that Fit for Use may be acceptable for some things but not others.

In our situation, we have Corporate engineer writing specifications that we (manufacturing plant) have told them is unachievable and unreasonable. We have backed with numerous tests data that shows the spec limitations are too narrow. End product performs as required and even age testing has shown there is no problem even though we don't meet a componenet spec limit.

Are there other issues at play here rather than true 'Fit for Use' philosophy...Yes, but this is the only tool we can use. Corp refuses to change the spec, we tell them we cannot provide part to spec, they tell us to run the best we can and ship out product.

It is all very :bonk: :frust:

PS: Figured I should add this to make the situation clearer -
We do not custom manufacture...Our company (Corp Eng) designs and calls out specs. The customer is guaranteed the product will perform to specifications, which it does.

Geoff Cotton

Quite Involved in Discussions
If we get this situation we simply carry out a Ppk or Cpk study.

When it fails (and by the sound of it, it will) we turn the process off and wait for the screams.

If we are forced to turn it back on we simple hit all the production with a Nonconformance ticket and refuse to pass it to stock until someone high in the food chain signs for it.

Then load the PPM figure against those causing the problem, for some reason they don't like it when we do that. Especially when the PPM report gets interigated (weekly) by the Senior Management Team.

(You soon become unpopular, but they learn very fast)


Mike S.

Happy to be Alive
Trusted Information Resource

I agree with db that the context or situation where the term "fit for use" is used means alot. In your situation -- a valve going into a nuclear reactor being out-of-spec. -- forget about it -- you did exactly the right thing.:)

Long ago I realized that higher-ups would often try to determine on their own if a product that was out of spec. was "fit for use" anyway. Often these folks did not have the technical skill to determine that -- they just looked at potential dollars added to the ship-out totals and tried to calculate the risk of getting caught. Too bad, I would not sign-off on it nor would I allow my technicians to do it. They were all told in no uncertain terms thay had the right to refuse to sign-off on bad stuff even to the President. To protect their job, they could allow a VP or President to sign for them, but they had the right to refuse to sign themselves and there were occasions where they exercised this right to a blustering bigwig who sometimes backed down instead of put their name on the line. (It was okay for a lowly tech to get blamed if it backfired, but not them.)

The next quality manual I did very specifically stated that NO ONE in the company had the authority to authorize a deviation to a customer's specification except the customer, and it HAD to be in writing. I had the President sign off on it for backing. On a few occasions I had Salesguys and a VP of Production scream at me for my lack of ability to "see the gray areas" but I always told them if they had a problem we would go to the President and let him decide based on the facts. Since the Prez was the top dog and he approved the policy, only he could deviate from it. On rare occasions, where the technical people truly felt there would be no harm, the Prez did break his own rule. The Prez himself once chastized me on this "gray area" stuff during a performance review (a VP complained to him) and I reminded him that I still gave him the opportunity to overrule me but I had to play if straight, period. "That's why you get paid the big bucks" I told him and he eventually agreed. He kinda liked the power I think.

It may not work everywhere, but it works for me. Mostly.

I forgot to say, none of this stuff we sold was life and death kinda stuff like Lee's!!!

Mike S.


Its great having details from various different situations and its good to demonstrate actions for and against.

With the tolerance that organisation worked to, as you can imagine, we had many instances that parts would fall out of tolerance. Reporting to the ‘President’ (we call them directors, who in turn are lead by a managing director) would prove time consuming to say the least.

If we had an instance that we knew we could not achieve a tolerance, the policy employed was to communicate the failure with the Quality Manager (When I was promoted . . . Me) who would in turn inform the customer of the failure who would give/ decline a concession.

We would then assign SPC techniques to fully understand the process capability using ppk etc. And then report back to the customer who would in turn either accept or decline the captured data.

I frequently had instances were they declined the data. We sub-contracted those item’s out to an organisation with machines that could.





First of all I notice you have been a member for a year and have only 8 posts. What a shame. Your posts are excellent. We need more input from folks like you. :bigwave:

Anyway on to your concern.

I can add little, other than agree with others in their views. And congratulate you on your promotion. It appears that you are now in a position to effect some real change.

Tell them that the only way it goes is if they sign for it. That there are criminal and civil liability issues and it is your job to protect the company from these. If they beleive it is ok they need to get authorization from the customer.

As for the Fitness for use issue, I simply don't think there is any room for fudging when you are talking about Nuclear, Gas, and oil industries. As for other areas a lot depends on factors such as are these "off the shelf" items? Do you do the design? Does you customer have to sign off on special designs? How much safety factor is designed in? (these are just off the top of my head.)
In these cases you might accept fitness for use, but demand their reason in writing. And with details.

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