To quarantine nonconforming material, identify it right away, tag it, move it to a marked and controlled area, record it in a log, and let only an authorized person decide what happens to it: rework, scrap, return or use under an approved deviation. The point is to keep bad parts from mixing with good ones. A tag with no log, or a red tag area nobody owns, is how nonconforming parts end up on the truck.
What quarantine is for
Parts that fail to meet the requirement can only hurt you if they get mixed back in. Quarantine is the physical barrier. It puts the suspect parts somewhere they cannot be picked up by mistake, and it leaves a paper trail that says what is there and why. ISO 9001 and IATF 16949 both expect nonconforming product to be identified and controlled. The way you do it on the floor is what decides whether it works.
Suspect or confirmed
Many plants use two states. Suspect parts might be bad: a lot from a process that just failed a check, or parts made between the last good check and the bad one. Confirmed parts have been measured and are nonconforming. Both get segregated. They get different tags so nobody scraps good parts or ships suspect ones.
A common scheme is red for confirmed nonconforming and yellow for hold or suspect. It does not matter which colors you pick. It matters that the scheme is written down, posted and the same in every department.
What goes on the tag
- Part number and description. Exactly as on the drawing or the traveler.
- Quantity. Counted, not estimated, and updated if parts are added.
- Lot or date code. So the parts can be traced back to the run.
- The reason. The defect in plain words and the requirement it failed, such as “burr over 0.2 mm on cross hole.”
- Where and when it was found, and by whom. Department, operation, date and initials.
- Status and disposition. Hold, rework, scrap or return, with the date and the name of the person who decided.
The area
A controlled area is marked, separate from good material and, where the risk is high, locked. Put it where nobody walks through it with a tote. Give it an owner, a person whose job it is to keep it clean and the log current. A red tag area with no owner turns into storage within a month.
How to do it, step by step
Stop and identify
The moment someone finds a bad part, they stop and tag what they have. Everyone on the floor should know they are allowed to do that, and that they will not be blamed for it.
Segregate the parts
Move them to the controlled area. Do not leave them on the machine, on a cart in the aisle or in a “temporary” spot.
Log it
Write the tag in the log with a number, the quantity and the reason. A tag with no entry in the log is a loose end.
Search wide
Check where else the same problem could be: parts in process, finished goods, stock in the warehouse, material in transit and anything already at the customer. Containment is the search, quarantine is the holding.
Notify
Tell quality, the supervisor and anyone downstream. If the parts could have shipped, tell the customer under your procedure.
Decide the disposition
Only an authorized person or a review group decides: rework, scrap, return to the supplier, or use as is under a formal, approved deviation. The operator who found them does not decide.
Carry it out and close the tag
Rework gets reinspected. Scrap is counted and destroyed so it cannot come back. Returns are packed and recorded. Update the log and remove the tag only when the parts are gone or released.
Mistakes that let bad parts escape
- Tags with no log. Tags fall off. A log is the only proof of what was held and what happened to it.
- Moving parts without paperwork. Anything moved in or out of the area without an entry is a mix-up waiting to happen.
- No aging check. Material that sits for months is a sign no one is deciding. Review the area weekly and chase anything old.
- Rework with no reinspection. A reworked part is a new part. Check it against the requirement before it goes back to good stock.
- Scrapping before you count it. You need the count for the cost, the supplier claim and the trace. Count first, then scrap.
- One person decides everything. Disposition on anything with customer or safety impact belongs to a group, with a record.
When the parts came from a supplier
Tag them and hold them the same way, and keep them as evidence until the supplier has responded. For the written request, see how to write a SCAR. Field Book 2 walks through the supplier containment and red tag step with a made-up case.
The NCM Red Tag Log keeps the tag numbers, quantities and dispositions in one sheet, and the Deviation Waiver Form covers the approved use-as-is case.
Questions people ask
What is the difference between containment and quarantine?
Quarantine holds the bad parts you have found. Containment is wider: the search for every other suspect part, plus the actions that protect the customer until the cause is fixed.
Who is allowed to release quarantined material?
Only the person or group named in your procedure, often quality or a material review group. The operator who found the parts and the person who made them should not release them.
How long can parts stay in the red tag area?
As short a time as possible. Set a limit in your procedure, such as a week, and review anything older at a standing meeting.
Do I need a physical cage?
Not always. A marked, separate area can be enough for low-risk parts. Safety or special characteristics, and high-value or tempting material, justify a locked one.
Can I rework nonconforming parts?
Yes, when your procedure allows it for that defect, with an approved method and a full reinspection afterward. If the customer requires approval for rework, get it first.