Calibration Requirements after Exceeding the Calibration Due Date

[azamiruddin]

Hi all,

I dont know wether this thread already exist or not, cannot find it.

I am in charge of company's calibration lab.

I have a problem that required help from Elsmar Cove members. Within our composites manufacturing process, there is a process that need composites to be cured inside a pressurized oven (@300F++). this oven calibration interval is 30days (customer req.). now it is already exceeding due date at about 31days and it is allowable per our internal procedure (10% extension). calibration of this oven will expired on 31st May. actual expired date was 28th May. so, on 30th May 11.59:59pm and beyond, this oven no longer can be used (on paper). we will not allow them to start any cure after 12.00:00am 31st May.

my question (also asked by production team), IF composites cure start at 9.00pm on 30th May, and finish cure at about 3.00am 31st May, is that cure acceptable or not?

p/s:
1) Oven = Autoclave we called it here.
2) 10% extension = set by company, i dont quite agree with this number, can i revised it to 25% ?

[v9991]

In Reply to Parent Post by azamiruddin

my question (also asked by production team), IF composites cure start at 9.00pm on 30th May, and finish cure at about 3.00am 31st May, is that cure acceptable or not?

speaking compliance-''wise'', one must not allow the cure to start at first; however,technically it could be done on ''deviation'' that, batch release will only happen after suitable verification measures of oven-performance as identified/commited steps (using additional probe such as ones used during calibration etc.,additional qc steps etc.,) suitable in deviation-approval.

Now same can be extended for processing multiple batches, depending on the equipment reliability, dependability of methods to verify the product&process performance, (some times we do subject such batches to additional performance studies ...) and risk there-off from any negative fall out such as product failure, customer complaints etc.,

but these practices actually dilute the systems, and has tendency to become a practice; + its not always easy to justify the deviations and does not ad value to aditional steps being implemented..

In Reply to Parent Post by azamiruddin

2) 10% extension = set by company, i dont quite agree with this number, can i revised it to 25% ?

You will find other threads on similar topic (just at the end of page... see "similar threads")

However, it depends on the trends of calibration - failures - breakdowns - RCAs traceable to the performance of given equipment ... Which will determine the feasibility of revising the extension of grace period for re-calibration. (or frequency)

[Jennifer Kirley]

I agree that knowing the gauge will fall out of compliance during the process, that gauge ought not be used at start of process. However, if your system allows it a deviation might (depends on customer, industry, standard etc.) be allowed so long as you can verify the product is, in fact conforming even though the gauge is out of calibration cycle.

[BradM]

You state that you have a customer requirement here.
Exactly what is the requirement?

[azamiruddin]

Thank you for the response.

In Reply to Parent Post by BradM

You state that you have a customer requirement here.
Exactly what is the requirement?

Brad, my end-customer is Boeing, they require us to perform 30 days calibration interval on all machines that perform temperature & pressure composites cure cycle. This figure quite tight for us due to manpower and calibrator (comparator) limitation.

[BradM]

In Reply to Parent Post by azamiruddin

Thank you for the response.



Brad, my end-customer is Boeing, they require us to perform 30 days calibration interval on all machines that perform temperature & pressure composites cure cycle. This figure quite tight for us due to manpower and calibrator (comparator) limitation.

Well, the reason I ask is that you are kind of bound by customer requirements. Unless, you have an exception in the purchase order or something. Otherwise, anything past 30 days is past due.

I would think that given successful calibration events and if you have monitoring/ recording equipment that could be relaxed. Otherwise I would charge them more.

[EEJen]

Calibration schedules are a risk management tool. Expanding by 25% may increase your risk but you need to know how much product is measured with the tool. If the tool is used infrequently and low volume of product then your risk is lower.

My experience with Boeing is that compliance to the schedule is important. If calibration schedule conflicts with delivery schedule, I would request a waiver from them explaining the delivery impact.

[blueicecube2]

as usual, perform an experiment and study data to back up whatever decision made i.e extension of calibration interval.

as the owner of the equipment, it is always good practice to convince yourself the equipment is indeed performing what it is designated to do before convincing others.. hehe

2 cents