Incoming Stock QC, where to start?

[juntothehan]

Hello, I have recently been tasked to implement working systems for my company's Warehouse. Currently we are experiencing a shortage of manpower and cannot afford to carry out IQC for majority of our incoming stocks. We have identified critical items that cannot proceed to production without IQC like electrical components, but even those items are bought in bulk and the IQC process takes an operator almost a whole week just to complete checking every single piece (thousands per order). We have tried solely relying on IPQC, but this has led to shortages which led to overall delay in production due to long lead time required from the suppliers when we place the order after encountering a non-conforming batch of stocks. Not to mention having a high wastage rate and causing us huge losses financially.

I have read from a few threads here on the DtS system which seems promising but I also want to ask if there are any other options that industry experts here can suggest?

 

[Ron Rompen]

Not sure what the 'DtS system is', however if you are doing 100% inspection on incoming components, then there is definitely an opportunity for improvement.
Is 100% really necessary? What is the reject rate that you are finding? When you DO find rejects, are they contained to a single lot/batch (at a time) or are they just generally scattered over multiple lots? There are (potential) actions that you can take for either scenario.

 

[Mike S.]

Why do you check every single piece? The only reason to check every single piece vs. sampling batches is if you are trying to screen out batches with very low defect rates.

I doubt your problem is very low defect rates, as you mention the high "wastage rate" .

So why not do statistical sampling at incoming?

 

[juntothehan]

Not sure what the 'DtS system is', however if you are doing 100% inspection on incoming components, then there is definitely an opportunity for improvement.
Is 100% really necessary? What is the reject rate that you are finding? When you DO find rejects, are they contained to a single lot/batch (at a time) or are they just generally scattered over multiple lots? There are (potential) actions that you can take for either scenario.

Hi Ron, thanks for your input. The latest case that has led us to checking every single piece was due to finding defects scattered across multiple lots. We used to do statistical sampling without IPQC before this. Also, DtS that I read about is Dock to Stock.

 

[juntothehan]

Why do you check every single piece? The only reason to check every single piece vs. sampling batches is if you are trying to screen out batches with very low defect rates.

I doubt your problem is very low defect rates, as you mention the high "wastage rate" .

So why not do statistical sampling at incoming?

Hi Mike, thanks for your input. We were doing statistical sampling, until we encountered scattered defects across multiple lots. The objective of my question is to prevent this from happening again, where incoming checks can catch cases like these in a short time. As in while defects scattered across multiple lots might be a rare occurrence, it is still something I want to catch.

 

[Ron Rompen]

If you are finding scattered defects, then I would look at in-line testing of your parts. Yes, you lose some investment of time/labor/material, however it will (possibly) be compensated for by better throughput.
You should also discuss with your supplier - make them aware of your plans, and ensure they understand that rejected/failed parts will be costed back to them - drive them to improve THEIR processes as well.

 

[Mike S.]

What does scattered defects across multiple lots mean? Give us some numbers. How many lots are defect free? What kinds of defects vs lot size do you see in defective lots? How long does it take to test 1 part?