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Handover to Manufacturing: What NOT to do & Best Practices

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Let’s focus on your handover to manufacturing (specifically looking at hard goods with mechanical elements and some electronic/electrical parts). 

Product handover to your manufacturer is a structured process of actions you follow to ensure a smooth transition from you to them so the product ends up being made to your specifications and requirements and the risks of issues before product launch are minimized.

You’ll learn:

  • What a product handover to manufacturing is.
  • The drawbacks of not following a structured process and how not to hand over.
  • What the best practices for handover are so you can follow them to streamline your next project.

 

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Listen to the audio here.

 

Who needs to hand over their product to a manufacturer and why?

Businesses with simple products, for example, may not need to handover to manufacturing as production can be handled in-house. However, most of the people we talk to want a low unit cost, the ability to make a profit margin and be cost-competitive in the market, and aim to sell tens to hundreds of thousands of products, therefore this can’t be handled in-house and working with a factory is required. This manufacturer will also ideally contribute by reviewing the product design (DFM) and handling the industrialization of the product (the latter stages of the NPI process) so it makes it into mass production in a streamlined way, with acceptable risks and costs. So the question is, when you’re ready to work with the factory, what information do they need to do their job smoothly? (00:50)

 

How to handover to manufacturing the WRONG way.

The common bad practice for handing over to manufacturers is to work with product designers and, when a prototype and design files are ready, to ‘throw it over the wall’ to the factory without a DFM review. But leaving it to them just to produce the product and having no dialogue about how to manufacture that design (typically a DFM review) is very risky, as you may not have any feedback about it related to the manufacturing and testing process, how they will make it or if they are even able to, which production processes will be used, possible drawbacks, and suggested alternatives.

Here are a couple of examples of how a manufacturer’s DFM review can help you:

Plastic enclosures

A working prototype is not the same as a mass-produced product and the manufacturer may have to suggest changes to the product to make it in large quantities. For example, a 3D-printed plastic enclosure may look great, but it might not be possible for plastic injection molding to achieve the same shape, or the manufacturer might be able to provide feedback about the molds that could save thousands of dollars (as mold tooling is quite an expensive investment).

Metal part finishes

You may want metal parts to be anodized, but in some case this may result in porosity and quality problems. A manufacturer should alert you to this risk and provide alternatives, but if that dialogue never occurs you can expect them to go ahead and potentially provide you with parts that don’t reach your expectations. Perhaps you have a metal part that will be used on ocean-going boats, and the suggestion is stainless steel, but will this cope with the corrosive salt water? Maybe the metal parts will need an additional powder coating for protection? (04:22)

 

Questions about the product that need to be answered.

The problem is that some entrepreneurs and businesses never speak with the manufacturer about the products so questions like the above remain unanswered. The focus is on ‘getting the product to work’ and having a great prototype in hand, but asking and answering important questions related to actually mass producing the product are missed:

  • Is the product fit for how people will use it (customer use cases)?
  • How will it be made and with which production processes?
  • What is the impact on cost, quality, and timing of the processes?
  • How will the product be tested?
  • How will it be assembled, and will the production operator require guidance to assemble it correctly (such as jigs and fixtures)?
  • How can mistake-proofing be implemented?

Industrial designers and design houses doing product and engineering design may not take DFM into account and ask these questions, leading to real difficulties once the product reaches production. (09:57)

 

Who will do the DFM?

An experienced contract manufacturer that has engineering staff on their team who can perform a DFM review bearing in mind their and their suppliers’ processes is a benefit as they can suggest achievable changes. In addition, you can possibly expect them to suggest reliability improvements at the same time, although doing DFR during prototyping is key for obtaining good reliability. (12:55)

 

What can happen if you just throw designs over the wall to a manufacturer without doing a DFM review?

Manufacturers’ incentives are usually to get products made and shipped ASAP so they can get paid, but they may not readily do a DFM review as this delays them. A recent customer came to us with a problem, as they had given immature product designs to the manufacturer who went ahead and fabricated plastic injection molds at great expense without doing a DFM review. Unfortunately, the product design needed to be changed and this meant that the mold tooling needed to be reworked and partly scrapped at great expense…this could have been avoided if the manufacturer had ben tasked with a DFM review or the customer had gotten third-party engineers to perform one before approaching the manufacturer.

Making changes to product design is best done as early as possible, as the later it happens the more it will cost as seen with the mold tooling, so if you are relying on your manufacturer to do a design review that could well result in design changes, you will need to start the hand over process earlier and bring them in while the product is still in the development stages of the NPI process. (15:32)

 

Handover to manufacturing best practices.

Several best practices will lead to a more streamlined handover to manufacturing:

  • Select a suitable “main supplier.” If you work with a reliable one already, they’re probably a good option. ODM and OEM manufacturers provide less control over the product design and project in general, so source a CM that is experienced in your kind of product if possible when you see relatively clearly what the product will be like. You may also like to source and nurture a backup supplier, as well.
  • Commercial considerations: find out how the CM bills for its work, terms of engagement, transparency of the supply chain, and if there are negative “hook in” effects (such as them specifying to retain ownership of your tooling), etc.
  • Provide a fairly high-level brief, and then more complete documentation (use case and application, initial user manual, initial BOM that provides a list of components and where they are located in the product and includes whether they’re custom-designed or off-the-shelf, critical performance targets such as the tongue required from a motor so it can be tested and validated, an expected quality level which should be realistic and the reliability target which impacts the type of components that should be sourced as they need to be able to reach the target and not fail early, etc.) as you need to start feeding the supplier information as part of the handover.
  • Start to rely on the CM and see where they fill gaps in your team’s capabilities or are just better, for example for sourcing work if the BOM is expensive, or reliability if that’s a competency of the CM, etc.
  • Mechanical drawings: DFM review, then decide who does the adjustments, your original design team or the CM? Work on the costing for tooling and part production, especially custom-designed ones. Also, provide the supplier with mature 2D drawings which show details about the product’s dimensions and tolerances and mention CMF, highlighting key ones.
  • Electronic design and embedded software: Do you need help with that from the supplier? Do you need to buy long lead-time components now? Ask these questions when handing over.
  • It’s too risky to fabricate tooling before your final prototype has been validated, and it’s usually better to let the CM prepare, assemble, and test the final prototype because they learn how the assembly is done and which operations are difficult, providing suggestions along the way. They will be able to provide a more accurate quote for assembly, testing, and packing work.
  • Hardware-software integration: This can take days or even weeks, especially if the software side is handled by the customer or a third party and not that manufacturer, so you need to plan for this and will ideally start integrating the two as early as possible. (18:15)

 

When is the handover to manufacturing complete?

The handover to manufacturing is more or less complete after the completion of EVT when the design is validated, works as intended, and the design will be frozen. Now, in the DVT phase, tooling can be fabricated for custom-designed parts, and once some of those parts come off the tooling and are validated functionally and aesthetically, some product prototypes can be made in small quantities and also tested. This can require a lot of trial and error, especially for aesthetic considerations, but by now the manufacturer should be taking charge and the customer and industrial designer just provide feedback to them. Finally, in this phase, the golden and limit samples will also be approved which are used to illustrate the customer’s requirements and acceptance criteria for products in mass production. (35:14)

 

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