Three perspectives needed after PCN notification

When a PCN notification is received, there are three perspectives that need to be considered on-site. By dividing the situation into these three categories, you can prevent confusion and omissions in your response.

■ Evaluation: Is this change okay?
We will verify whether the changes will affect the product's performance or quality. This evaluation does not necessarily involve conducting tests. It involves confirming whether a judgment can be made based on manufacturer information and past performance. If it can be determined that there are no problems based on existing information, additional testing is not necessary. Testing or verification may only be discussed if a judgment is difficult.

■ Switchover: When will the new specifications be implemented?
We will decide when to migrate to the updated product. Since PCN compatibility anticipates a migration to the updated product, we will need to determine when to switch. In practice, it is simple: if there are no problems, switch immediately; if we are unsure, postpone the switch.

■ Inventory: How long will we keep the old stock?
The amount of old stock to keep will be determined in line with the transition timing. If the transition is immediate, it's possible to keep stock to a minimum, but if the transition is delayed, a certain amount will need to be secured. The key point is to think of inventory as a means to adjust the transition timing.

The first thing you should look at is the "changes."

The first thing to check when implementing PCN changes is the nature of the changes. The complexity of the implementation will vary greatly depending on these changes. Applying the same changes to all PCNs will lead to unnecessary evaluations and oversights. Therefore, it is important to first understand exactly what changes will be made.

■ Changes and key points to note
There are various types of changes that are notified via PCN. Here, we will summarize some typical examples and the concepts behind each.

• Changes related to manufacturing conditions (e.g., manufacturing site, materials, suppliers)
→ While it may not directly affect the characteristics in all cases, it may have an impact depending on the conditions.
After reviewing the specifications and applicable conditions, we will consider additional checks as needed.

• Changes related to processes or design (e.g., changes to process flow, changes to design rules)
→ This may affect the characteristics and reliability.
Based on the evaluation, we will carefully determine whether or not to switch and when.

■ Start by considering the changes.
There is no predetermined approach to PCN compliance; the decision depends on the nature of the changes. Therefore, rather than focusing on "what level of change it is," it is important to understand specifically what will change and consider the appropriate response based on its impact.

Points to check during evaluation (what to look at and to what extent)

The evaluation process involves checking whether the changes will affect the product. However, it's important not to conduct tests blindly. The first thing to consider is whether the changes can be determined using existing information.

■ Cases where additional evaluation is not required
This applies when the changes are clearly non-impactful and all the necessary information is available. In this case, no new tests will be conducted; the issue can be addressed by simply reviewing the content.

■ Cases requiring confirmation
This is when the impact cannot be fully predicted. If there is a possibility of impact depending on the conditions, such as changes in manufacturing sites or materials, we will organize the specifications and usage conditions and perform the minimum necessary checks.

■ Cases requiring evaluation
These are changes that could affect characteristics or reliability. For changes related to processes or design, evaluation should be considered, and testing and verification should be considered as needed.

The evaluation criteria are simple: it's about deciding "how far to go with additional verification."

How to proceed with the transition (when to make the transition)

The next thing to consider is when to switch to the new specifications. With PCN compliance, it's common practice to proceed with the assumption of migrating to the updated product. Since manufacturers assume a transition to the new specifications, users need to consider when to make the switch.

■ If you switch immediately
This applies if the evaluation confirms that there are no problems.
- The changes will not affect performance or quality.
• No problems with the usage conditions.
• The impact on the site is minimal.
In this case, we will transition to the new specifications. However, in practice, not everything will switch over immediately. Due to lot and inventory considerations, the old product and the new specifications will coexist for a certain period. Therefore, we will clarify when the new specifications will be applied and manage them to prevent mixing of the old and new products during the transition.

■ When you want to delay the switch
If an immediate switch is not possible, we will allow a certain period of time to address the issue.
- Evaluation is not complete.
• Customer approval or authentication is required.
- Immediate changes are difficult due to equipment and production conditions.
In such cases, we use existing stock of the old product to gain time, and then switch over once the necessary conditions are met.

When implementing a transition, the key is not simply whether to "change quickly or delay." The practical point is to determine a suitable timing for the transition, taking into account evaluation results, customer requirements, and on-site constraints.

Inventory management strategies (how long to keep inventory)

The last thing to consider is how much of the old product to keep in stock. Inventory levels depend on the timing of the transition, but in practice, the transition period set by the manufacturer rarely matches your company's timing. Therefore, you can't simply think, "We'll switch over soon, so we'll only keep a minimum," but you need to factor in potential delays when planning your inventory.

■ Relationship between changeover timing and inventory
• If the plan is to switch over immediately: The basic principle is to keep inventory low, but also consider the possibility of a delay in the switchover.
- If you need to delay the transition: Secure sufficient inventory in addition to the required period.
- If the transition takes time: Plan and secure supplies in advance, taking into account the manufacturer's supply deadline.

■ Points that make inventory planning difficult
The difficulty in inventory management stems from the assumption that the transition may not proceed as planned.
- Evaluation and approval may be delayed.
- The switchover will be delayed due to on-site circumstances.
• The manufacturer has set a date for discontinuing supply.
Therefore, inventory levels should be considered not only in terms of the "necessary amount," but also in terms of a level that can cope even if the transition is delayed.

Inventory is not simply a matter of quantity; it's a means of absorbing the uncertainty of product transitions. It's crucial to determine a realistic inventory level that can be operated, taking into account the discrepancy between the manufacturer's transition timing and your own company's situation.

Basic steps for PCN implementation

As we have seen so far, PCN compliance can be organized from three perspectives: evaluation, transition, and inventory. In practice, following this flow in order will simplify the process. First, upon receiving the PCN, check the changes. Understanding what the changes are will determine the direction of subsequent actions.

Next, we determine how much evaluation is needed for the change. We assess whether the decision can be made based on existing information or if additional verification is required. Once we have a clear picture of the evaluation, we decide on the timing of the switchover based on that. We clarify whether to switch over immediately or to continue using the old product for a certain period.

Finally, we determine how much inventory to hold in line with the transition plan. We take into account that the transition may not proceed as planned and determine a level that is realistically manageable. PCN compliance tends to be a matter of individual judgment, but by organizing it in this way, we can proceed with evaluation, transition, and inventory management in a consistent manner.

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