Posted on 03 Dec, 2015 by Neil Sharp
The New Product Introduction (NPI) process is arguably one of the most crucial elements of contract electronics manufacturing. Contract electronics manufacturers (CEMs) that have robust NPI processes should be able to demonstrate to you that they are capable of consistently delivering quality product.
However, those that ignore this key phase, or pull out a dusty, outdated policy document only when their customers carry out an audit, may struggle to manufacture products to the same standard each month.
Many CEMs will talk about their NPI process and its importance - but what steps do they really take to guarantee that customers' products are introduced into their manufacturing operation in a tightly controlled manner? And does a product really have to be "new" to qualify for this extra level of attention and care?
In this blog post, we aim to answer both of these questions by listing out the seven steps credible CEMs should be taking to ensure their production process is repeatable.
Before looking at the seven steps, let’s start by stating that the NPI process doesn’t have to be limited to brand new products or designs. While these should qualify by default, any other product that is essentially "new" to the CEM should also be put through the process. Regardless of whether your design is six weeks or six years old, if the CEM hasn’t built the product before, their engineering teams will want to prove out their internal processes. This requires them to oversee the first couple of batches before handing over fully to the production teams.
So, now we have cleared up that misnomer, let’s take a look at some of the critical steps CEMs should be taking.
The CEM will need a robust system in place to automatically highlight "new" builds to their engineering team. With new orders being loaded throughout the day, across a wide range of customers, this shouldn’t be left to chance or rely on a manual process. Ideally, new builds will be flagged to the engineering team on some kind of automated overnight report.
Among other things, the report should state the customer’s name, part number, batch quantity, the unique works order number, customer request date, order acknowledgment date and the name of the customer account manager that loaded the order. On receipt of this information, the engineering team should then create a unique NPI number for the job, which can then be referenced at a later stage on any reports or documentation they create.
2. Data verification
The engineering team should then double check they have all the data and equipment they need for the first build. It’s not uncommon for some data to follow after the initial request for quote (RFQ). While the lack of some data won’t necessarily impact the pricing, it could grind the assembly to a halt. The latest revision software or pieces of customer supplied test equipment are good examples of this.
Once the NPI engineer is satisfied they have all the required data, they will start creating bespoke build packs, ordering solder stencils or pallets and writing programmes for the surface mount equipment. All of this will then be released to their internal document control platform so it can be securely stored, accessed and then updated if needed in a controlled environment.
To make sure the NPI build documents really stand out, some CEMs have in place a clearly defined colour coded document system. This makes it obvious where each works order sits in the production life cycle and is an effective way of visually raising awareness of NPI builds to other departments.
3. Batch size
Next the CEM provider will need to determine how many products they plan to run in the first batch. A mistake sometimes made by some CEMs and an all too common mistake made by original equipment manufacturers (OEMs), is producing the entire batch quantity on the first run.
By its very nature, the NPI process is designed to prove out the build process prior to volume manufacturing. If any manufacturing issues are found, or design tweaks need making, it’s important these are rectified in the most cost-effective manner. Setting the pick and place machines to run the entire batch only to find a problem at the inspection stage has the potential to cost both the CEM and OEM significant amounts of time and money.
Best practice advice, therefore, is to run a smaller quantity NPI batch first while ensuring the remainder of the material required for the works order is ready to follow once the first stage has been signed off. The actual batch size will vary from job to job. However, determining factors for your CEM will include PCB panelisation, complexity, test requirements, and the completeness of your build data.
The CEM will also want to understand if the OEM requires the first off build shipping in for further testing, prior to running the remainder of the NPI batch. If the OEM is planning on carrying out extra tests and checks, this needs to be communicated in advance so that any potential delays can be factored into the overall lead time.
An NPI Engineer will then oversee all stages of assembly, including any test requirements. Any observations they have during these stages should be recorded on some kind of traveller document. This allows critical information to be incorporated into the original build pack and may take the form of additional care points, notes or images to help improve the quality or efficiency of the next batch.
5. Sign off and shipment
Prior to shipment, the NPI engineer should be responsible for "signing off" the build. Ideally, the CEM provider will have an automated system or process in place to avoid freshly built product shipping straight out of the door without a final check. Providing there are no issues, this extra process shouldn’t create any bottlenecks.
If, however, the NPI engineer is not happy to release the product, due to, for example, a design or test issue, they will need to communicate this to the customer account manager, who can tell the OEM and seek resolution.
6. Status change
Following shipment, providing all parties sign off the delivery, the CEM will then change the production status of future builds for the same product. The number of different levels will differ between each CEM provider, but you should expect to see something like NPI, pre-production and then volume build.
Along with an obvious change to the colour coding, the level of engineering support should also reduce as your product moves further towards volume build. If, for any reason, things change at a later date - for example, an Engineering Change Note is issued - the CEM’s system must be flexible enough to allow them to go backwards (i.e. change a volume build back to NPI status).
To complete the process, the CEM provider should produce an NPI report. These reports help clarify the physical build process the product has undertaken while documenting and communicating any issues found during assembly. Ideally, these reports will list out the specific details of the build, such as the part number, revision levels, the RoHS status and engineer responsible, etc. In addition, these will often include top and bottom images of the PCBA, outline the process flow, highlight material or build observations, as well as raising potential design issues and suggested recommendations.
Providing your CEM provider has a similar process in place then there should be no reason that new designs, or more mature products you have been building in-house for several years, cannot be produced consistently by them. If, however, there doesn’t appear to be a thoroughly documented process in place, or it is only used on "special" occasions, you may want to challenge them a little more on how they control repeatability within their manufacturing process.
Image by Jennifer Bradford