Validation & which processes are called special processes & why not all the processes

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vasudev

what is validition of special process (man,M/c or operations) & which processes are called special processes & why not all the processes are under scope of validation
 

Colin

Quite Involved in Discussions
Re: validition & which processes are called special processes & why not all the proce

In most situations it is possible to check/verify that a job has been done to the required standard by conducting some sort of inspection activity e.g. you manufacture a simple component and then you check the length and diameter.

On other occasions you may perform a process such as sticking together 2 pieces of paper and the only way to check they are stuck properly is to tear them apart. Therefore, it falls into this category we used to define as 'special processes'. Because we cannot verify that the job is done to the required standard, we emphasise the control aspects of the process such as what type of glue, what temperature/humidity, how much glue, held together for how long, under what pressure, etc.

These parameters would be established beforehand (through trials perhaps) in order to provide as much assurance as possible that the job works as required.
 
V

vasudev

Re: validition & which processes are called special processes & why not all the proce

so do we have to validate the process every time before start of the production...

you also mentioned that "These parameters would be established beforehand (through trials perhaps) in order to provide as much assurance as possible that the job works as required"

than do we have to validate any process in defined interval... if so than why???... to be more specific we are doing co2 welding for small covers, brackets, cabinets.... now the question is if we have experienced welder who is doing welding for last 10years than why do we say that you need to validiate welder... we have predifined welding chart which specify settings to be done while welding perticular part than why do we still need to validiate welding process after 6 months or 1year

In most situations it is possible to check/verify that a job has been done to the required standard by conducting some sort of inspection activity e.g. you manufacture a simple component and then you check the length and diameter.

On other occasions you may perform a process such as sticking together 2 pieces of paper and the only way to check they are stuck properly is to tear them apart. Therefore, it falls into this category we used to define as 'special processes'. Because we cannot verify that the job is done to the required standard, we emphasise the control aspects of the process such as what type of glue, what temperature/humidity, how much glue, held together for how long, under what pressure, etc.

These parameters would be established beforehand (through trials perhaps) in order to provide as much assurance as possible that the job works as required.
 

Colin

Quite Involved in Discussions
Re: validition & which processes are called special processes & why not all the proce

Revalidation only needs to be done 'as applicable'. If the welders need refresher training or 're-coding' periodically then go ahead. If the criticality of the work you are doing is low and the other controls are all in place then the need to do revalidation is less or not required at all.

You can verify the success of the welding process by the number of nonconformaces created, the number of complaints and returns etc. Obviously, if the work is more critical you cannot wait for things to go wrong before acting.
 

CarolX

Trusted Information Resource
Re: validition & which processes are called special processes & why not all the proce

so do we have to validate the process every time before start of the production...

vasudev,

That depends on what the process is.

For example - on our paint line, we perform certain checks on the process at the begining. We check the titration of the wash line chemicals, we verify the temperatures and line speed of the curing oven.

As Colpart said - revalidate as applicable.
 
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vasudev

Re: validition & which processes are called special processes & why not all the proce

what if we are doing 10% of jobs which require pressure testing (critical welding for oil tanks) & 95% are just covers,cabinets... even we checked rejection level of this oil tanks which we supply @750 a year & for last 10 years we are supplying it where in we had 3 rejections so far from customer... that too almost 3 years back than after as on today no rejections so what do you suggest


Revalidation only needs to be done 'as applicable'. If the welders need refresher training or 're-coding' periodically then go ahead. If the criticality of the work you are doing is low and the other controls are all in place then the need to do revalidation is less or not required at all.

You can verify the success of the welding process by the number of nonconformaces created, the number of complaints and returns etc. Obviously, if the work is more critical you cannot wait for things to go wrong before acting.
 
V

vasudev

Re: validition & which processes are called special processes & why not all the proce

we are in the bussiness of sheet metal fabrication... hence welding is one of the process.... if we weld as per the set perameters like current, wire feed, gas feed than what should be the freqency of validation of process or validatoin of welders....

vasudev,

That depends on what the process is.

For example - on our paint line, we perform certain checks on the process at the begining. We check the titration of the wash line chemicals, we verify the temperatures and line speed of the curing oven.

As Colpart said - revalidate as applicable.
 

Stijloor

Leader
Super Moderator
Re: validition & which processes are called special processes & why not all the proce

what if we are doing 10% of jobs which require pressure testing (critical welding for oil tanks) & 95% are just covers,cabinets... even we checked rejection level of this oil tanks which we supply @750 a year & for last 10 years we are supplying it where in we had 3 rejections so far from customer... that too almost 3 years back than after as on today no rejections so what do you suggest

You must be able to demonstrate that the (welding) process is able to deliver the goods. In other words, that the welding process is capable of meeting the requirements. How you validate that is your decision. There is no requirement that states how you must validate, only that the process is validated. It seems that you have sufficient information/records available (competent welders, suitable welding equipment, good work instructions, etc.) to make that happen.

Stijloor.
 
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CarolX

Trusted Information Resource
Re: validition & which processes are called special processes & why not all the proce

what if we are doing 10% of jobs which require pressure testing (critical welding for oil tanks) & 95% are just covers,cabinets... even we checked rejection level of this oil tanks which we supply @750 a year & for last 10 years we are supplying it where in we had 3 rejections so far from customer... that too almost 3 years back than after as on today no rejections so what do you suggest

Are you performing 100% pressure testing of the oil tanks? If you are - I would consider that continual validation of the process.
 
M

MysterHK

Re: validition & which processes are called special processes & why not all the proce

we are in the bussiness of sheet metal fabrication... hence welding is one of the process.... if we weld as per the set perameters like current, wire feed, gas feed than what should be the freqency of validation of process or validatoin of welders....

I'm not sure if this maybe related, but I'm going to post this anyway.

Last night at work, I was checking an order that just came off the brake and went straight to welding. The print's weld symbol called out for gas tungsten arc welding on all the seams and corners. The welder who was doing the job used flux-cored arc welding.

Here's my situation:

1. It was getting close to quitting time and only 25% of the order was completed.

2. I could conceivably reject all 25% of those parts because no shielding gas was used to protect the welds against atmospheric contamination depending upon the final application of the part.

3. I'm planning to talk this over with the production manager today, because it's possible that the print might be in the process of being revised based on the final application of the part where the gas shielding requirement is non-essential.

4. It's possible that the print is not being revised and the production manager will agree with me, and we may need to scrap all of those parts or we may need to call the customer and tell him that "X" amount of parts were done with flux-cored arc welding and the customer may accept or reject them.

Based on this, am I performing some sort of validation or is it strictly a QC process? :confused:

One more example:

If was doing a shear test on a resistance spot weld application on a part and I signed a certificate - would that be considered validation? :confused:

I am thinking that having some accompanying signed certificate with each product shipped to the customer is validation. Please correct me, if I'm wrong.
 
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