Sometimes you find yr self with no references or standards for yr process performance, how can you determine yr acceptence criteria in a scientifc way?

this could be applicable some times to quality control tests too,do you use special statistical Techniques to get yr own criterias ?

I would build up a history of performance and from that apply SPC to determine what my control limits should be.

Determine what your customers want, and need. May not be the same thing.
Benchmark your competitors products or services. Can you measure the differences? What is the customer perception of their products/services? How does your performance measure up, what are the gaps? What do your sales people have to feedback? Also as stated above, has the historical data been acceptable, and to what degree. This all may help.

Determine what your customers want, and need. May not be the same thing.
Benchmark your competitors products or services. Can you measure the differences? What is the customer perception of their products/services?

This is a very good suggestion. I'd rather ask the customer's standard/ requirementsand if there were'nt any, as in our case, most of the time products are being developed in the shop using only a product sample from the customer without product drawing or tolerances. We control the sample and set the standards from the sample, and from the sample we developm documents like Product Inspection Criterias, etc.:agree1:

freinds
regarding the quality control process , i,ve faced some problem in convincing the external auditors of conclusing yr own criteria from the history log you had ,they start to suspect of that log.
if i told them that those criterias are taken from our own experience,may be that would be better ???!!!

freinds
regarding the quality control process , i,ve faced some problem in convincing the external auditors of conclusing yr own criteria from the history log you had ,they start to suspect of that log.
if i told them that those criterias are taken from our own experience,may be that would be better ???!!!

I'm sorry but I don't understand. Why do the external auditors have a problem with the history log? What is the purpose of the history log? Aren't you recording the actual results or experiences on it?

I love making beef jerky. The recipe is mine, as is the process parameters. I decide how long to marinate the beef. I decide how long to dehydrate the jerky. I also decide whether the resulting product is acceptable. My acceptance criteria is strictly if the jerky meets my flavor and texture requirements.

Now, the question is why must the acceptance criteria be developed in a scientific manner?

they didint raise any nonconformities for the date ,but they show unsatisfaction since i have used the standard deviation for some data for three weeks ?they expect more than that period,and more professional statistical techniques?

and for me i think the values were little bit high as ( -+values ),this is why i asked for yr statistical way to get those ( -+values )?

thanx

7.5.1 says that you need carry out production under controlled conditions - one of the controls being "the availability of information that describes the characteristics of the product". YOur product would, I guess, fall into that category. You get a set of results, based upon in-house established tests, which determine if it's ok or not.

Even if you can't get a yes / no result from a test, 7.5.2 opens the door for you to set your own guidelines and parameters if it can't be measured. An example I've heard of here is the manufacture of soap - you can have all the fancy, viscosity, cone penetrometer, lubricity tests there is, but the best way to determine if it's right was an old bloke who had been testing the stuff for years and looked at how it fell off a trowel. Sometimes, you need to set your own guidelines and so long as you meet the requirements of equipment, training, traceability, frequency, documentation and "Pass / Fail" points, you can do whatever you want. Any auditor who has a problem with it needs to read up on the standard a bit better....

I agree that use of statistical data (especially the latest info possible) is important and he was perhaps setting an area of impovement with how SPC is used and contolled within your company. They have to find something you know....