Well Milk I have a few suggestions for you but it's hard to give specific advice without knowing your entire situation.
Is your plant under any GFSI food safety standard like SQF, BRC, FSSC?
Do you have a food safety team?
Basically this is what I would suggest:
Complaint comes into your facility (from whatever route phone, email, letter etc)
Log complaint into a database and assign a complaint number. They work good serialized by year so the first complaint of 2014 could look like this (14-0001) or something like that.
The log could have information like what product it was, the lot code of the product, description of the complaint, date of complaint, date of correction, what was the correction, etc.)
Perform a preliminary investigation with quality personnel.
Take all of the information to your next food safety team meeting or management meeting... wherever is the most appropriate place for the conversation with other managers and personnel.
Assign someone to perform a more in depth evaluation of the situation (this could be maintenance, operations, etc)
Set a date for further review - this shouldn't be too long only about a week or so.
Next meeting try to come up with what the root cause was. You can use things like a Fish Bone diagram or other such things.
Implement a change as appropriate to mitigate the risk of the problem happening again.
Evaluate the change and see if the problem has happened again or not.
If it has happened again go back to investigation / brainstorming
If it hasn't happened again close out the complaint with the correction on your spreadsheet/database.
Communicate the complaint and what fixed the problem ta the next management review (if you have those)
The important thing is to make sure you document everything. In your meeting notes make sure it's documented. In your management review make sure it's documented. This shows that you received a complaint and followed through. Insert communication with the customer in whatever way your company communicates.
Some complaints you will be able to tell if they are attributable to your facility by the food safety team meeting. For example:
One place I worked we received a complaint about a piece of plastic in the food. We looked at the retrieved sample and it looked like a little circle thing you put in the hole where screws go in a door frame. The Quality Manager had me walk around the entire facility to see if we had any that looked like that in place. I went through the entire facility and found that the hole plugs we used didn't look anything like what we received from the complaint. The Quality Manager took it to the other managers who had never seen a piece of plastic like that before. We told corporate that we didn't believe, due to our investigation, that we could have possibly put it in the food. Now corporate does their things, apologize, send coupons, or whatever... I don't know because I was just a lowly quality technician. But we did our process and found the fault was not ours.
