Start of Production is sometimes humorously referred to as the “Start of Panic.” There is a reason for that. It is a real test of an organization’s ability to manufacture and deliver parts to the customer at the required level — both in terms of quality and volume.
From this milestone onward, customer volume requirements typically increase week by week, effectively telling the organization: “Now prove that you are ready.”
What Does Start of Production Mean?
Start of Production, commonly abbreviated as SoP, marks the official beginning of series production.
From the customer’s perspective, this is the point from which the supplier is expected to manufacture and deliver parts according to the agreed demand, quality requirements, and delivery schedule.
From the supplier’s perspective, however, the situation is much more complex. By SoP, the following should already be ready:
- the product,
- the production process,
- the measurement system,
- the required documentation,
- implemented logistics requirements,
- approved sub-suppliers.
A single milestone therefore brings together the work of Quality, Production, Logistics, Purchasing, Maintenance, New Product Introduction/Launch teams, and Supplier Management.
This is why preparation for Start of Production should never begin just one month before the launch.
At that stage, there may still be enough time to close minor actions. However, it is extremely difficult to stabilize an unstable process, significantly increase production capacity, or repeat product validation within just a few weeks. In the latter case, an additional customer-approved deviation may also be required.
Customer SoP vs. Supplier SoP
A supplier should clearly distinguish between the customer’s SoP date and the date on which the supplier itself must begin series production.
If an OEM starts vehicle assembly on October 1, the supplier’s parts must obviously arrive at the customer’s plant earlier.
The supplier must consider:
- production lead time,
- inspection time,
- packaging,
- transportation,
- inventory within the supply chain,
- time required to react in the event of a quality or logistics issue.
A Tier 1 supplier may therefore need to start series production several days or even weeks before the customer plant’s official SoP.
A Tier 2 supplier must be ready even earlier because its component is first delivered to the Tier 1 supplier, where it is used in the next stage of the manufacturing process.
Failing to make this distinction leads to a common mistake: everyone works toward the customer’s SoP date even though the final parts should already be in the customer’s warehouse or on the production line by then.
The first question should therefore be:
When does the customer need the first production parts — not when does the customer start production?
Start of Production, APQP and PPAP
SoP is not a standalone event separated from APQP.
It is the result of activities carried out throughout the entire project — from requirements analysis, tooling development and process preparation through validation and final production part approval.
In simplified form, the road to series production may look like this:
Customer Requirements → Product & Process Design → Tooling Development → Production Trials → Validation → PPAP → Run at Rate → SoP → Safe Launch
The exact sequence of individual activities may vary depending on the customer and the project.
However, the fundamental principle remains unchanged: before series deliveries begin, the supplier should have objective evidence that both the product and the manufacturing process meet the agreed requirements.
Does PPAP Have to Be Approved Before SoP?
The standard expectation is that PPAP approval should be obtained before series deliveries begin.
In practice, however, situations may occur in which the customer grants interim approval or allows production based on an approved deviation.
Possible reasons include:
- incomplete validation testing,
- a temporary inspection method,
- temporary tooling,
- outstanding approval of one of the subcomponents.
Such a status does not mean that the issue can simply be postponed.
The supplier should always know the answers to four questions:
- Which requirement is not yet fully met?
- How is the customer protected until the issue is closed?
- Who is responsible for closing the open action?
- Until what date has the customer approved the deviation?
The worst-case scenario occurs when PPAP has a conditional or interim status but is treated internally as if full approval had already been granted.
The deadline passes, actions remain open, and during the next gate review it becomes clear that nobody has been monitoring the conditions attached to the customer’s approval.
Start of Production Is Not the Same as Commercial Launch
SoP appears earlier in the new product launch timeline than the Commercial Launch.
At this stage, the OEM begins producing vehicles or final products that are intended to achieve saleable status, meaning that they can ultimately be delivered to end customers.
The Commercial Launch usually takes place several weeks later.
There is an important aspect to remember here. Between SoP and Commercial Launch, production volumes may increase very quickly because the manufacturer needs to build sufficient stock before the vehicle officially enters the market.
OEMs need to manufacture enough vehicles to supply dealerships and distribution networks before customers arrive to see, test, and purchase the new model.
You have probably seen advertisements such as:
“Join us for the launch weekend of the new model.”
This is much closer to what we mean by the Commercial Launch.
Another interesting activity during this period is the production of a dedicated batch of vehicles for media and press activities.
Start of Production and Quality Complaints
There is an interesting way of looking at quality complaints during a launch.
If a problem is going to occur, it is far better for it to be identified and resolved before Commercial Launch rather than after it.
This does not mean that suppliers should intentionally generate complaints. Quite the opposite. The objective is to identify as many weaknesses as possible during the pre-launch phase, while there is still time to react before full commercial production begins.
There is also another reason why the exact launch status of a part can matter.
Some automotive manufacturers define specific rules in their supplier performance requirements according to which only complaints related to parts with a current production or commercial launch status affect certain supplier performance indicators or the supplier’s bid list status.
This is why you should carefully review your customer’s supplier quality manuals and complaint management requirements.
You may find provisions stating that supplier performance is measured only for parts shipped under current production status.
If the status of the complained part is still classified as pre-launch phase, the complaint may relate to parts delivered for prototype, pre-series, pilot, or other launch-related vehicle builds.
However, one thing does not change.
It is still a quality complaint and it can still generate significant additional costs related to:
- sorting,
- containment activities,
- potential part replacement,
- logistics,
- problem analysis,
- corrective actions.
Whether such a complaint affects the supplier’s formal performance rating depends on the specific rules defined by the customer.
Does Start of Production Occur Only Once During a Program?
The answer is: not necessarily.
During the life cycle of a vehicle, the customer may introduce a facelift, model-year change, or another major product update to maintain the attractiveness of the model. A facelift, for example, may take place approximately two or three years after the original launch.
From the OEM’s perspective, such a change may introduce another launch phase and new production milestones.
For suppliers, however, the situation may be different.
Imagine that we supply a braking system. During the facelift, the customer changes the bumpers, headlights, body colors, interior trim, and other vehicle features — but our braking system remains completely unchanged.
In such a situation, the customer’s systems may classify certain vehicle builds as being in the pre-launch phase because they relate to the facelift.
At the same time, from our perspective as the braking system supplier, nothing has changed. We are still supplying exactly the same part under normal current production conditions.
This distinction may become important when reviewing the status of a quality complaint.
If the customer classifies the affected vehicle or part as pre-launch, while the supplier considers the component to be part of regular current production, it is worth checking which classification applies according to the customer’s official supplier performance rules.
Depending on the Customer Specific Requirements, such a complaint may not affect the supplier’s bid list or supplier performance rating in the same way as a complaint related to regular current production.
Dariusz Kowalczyk
