The notification rarely comes as a surprise. There was an escape, then a second, then a complaint that reopened the first. What arrives is a short letter with an assigned level: CS1 or CS2. From that date, the plant ships under redundant inspection, and the exit is defined by your customer, not by you.
What Controlled Shipping Is
Controlled Shipping is a requirement imposed by the customer on a supplier when their normal controls failed to detect defects. It consists of adding a redundant inspection, in addition to the process, before the material leaves the factory, to ensure that no defective parts reach the customer while the cause is being rectified. Each certified shipment is identified and reported daily.
The most well-known levels are those of General Motors, but most automakers and Tier 1 suppliers have an equivalent scheme in their specific customer requirements. The details vary; the logic is the same.
CS1 and CS2 are not two sizes of the same requirement
The real difference between the two levels is not how much is inspected, but who generates the evidence.
| Level | Who Inspects | Who Pays | What It Means |
|---|---|---|---|
| CS1 | The supplier’s own personnel | The Supplier | The customer still accepts the evidence generated by their plant |
| CS2 | An independent third party, approved by the customer | The Supplier | The customer no longer accepts evidence generated by personnel who report to their plant management |
| GP12 | Supplier personnel, at an end-of-line station | The Supplier | Preventive early production containment; it is not a penalty |
In CS1 you contain your own resources: it is costly, but the process remains yours. CS2 changes the responsibility to the author of the evidence. Many programs also require the third party to report directly to the client. That is why CS2 is not a request for more inspection: it is a declaration that the client no longer trusts the internal evidence.
What Triggers It and How It Escalates
The triggers are predictable: a repeated escape, a defect in a safety or regulatory feature, an increase in PPM, or a containment that is not sustained. The escalation is also: many customer manuals automatically go from CS1 to CS2 after a defined number of days without clean data, or immediately when the feature is critical. If the problem persists, the next step is usually to hold off on new business until it is resolved.
Once the letter is issued, the level is almost never negotiable. What can be managed, and what most teams ignore, is the exit.
The Clean Point: The Date That Prevents Restarting Containment
Everything produced before the declared cut-off point is suspect, wherever it is: in your warehouse, in transit, on the customer’s dock, in the sequencing center, or in service stock. Declaring that point accurately, documenting it, and certifying only what comes after is what prevents a controlled shipping program from restarting just two weeks later, when an old item appears that no one has kept track of.
The Way Out: The Exit File
The clock does not stop when defects are fixed. It stops when the customer accepts the evidence that the defects have been fixed. The exit criteria are defined by each customer, but they almost always include the same elements:
- Consecutive clean data. A defined number of shipments or production days with no rejects, measured with the same criterion from start to finish.
- Trend by failure mode. Inspected quantities and defects by failure mode, per lot and per shift, showing before and after.
- Corrective action closed. The root cause identified and the action implemented by your engineering team.
- Effectiveness verified. Evidence that the action works, compared on the same basis as the initial measurement.
- Formal request. The exit request to the customer, backed by all of the above.
The most common mistake is to rush to complete that file at the end. It should be built from day one, while containment is in effect.
The Cost Is Never Just the Sorting Hours
A controlled shipping level costs urgent freight, hours from our own quality engineers dedicated to containment, an annotation in the scorecard that accompanies the next sourcing decision and, in some customers, the retention of new business while the level is open. That’s why the goal is never to operate well with Controlled Shipping: it’s to get out of it with a record that no one can dispute.
What a Third Party Brings to CS2
At RIDYS Group we perform the redundant CS1 and CS2 inspection as an independent third party. Our personnel do not belong to your organization, which is the specific condition a CS2 level requires. We issue the daily report by shift and by lot in your customer’s format when it is required, mobilize anything from a couple of people to three-shift coverage at multiple locations, and build the exit file from day one. If there is also material that needs intervention, we handle it as rework with an approved work instruction.
About our scope: The root cause analysis and corrective action are performed by your engineering team, and we do not represent your plant to your client. We work against the criteria, standards, and limit samples that you or your client define, and we report what we find without editing it.
Did You Receive a CS1 or CS2 Letter? Send us the level, the part numbers, and the shift schedule and we’ll respond with a mobilization plan and a rate.
