The Ability to Build a Prototype is Not Enough


Ken Haven

February 14, 2018

You’ve been working with your selected product development firm on developing the next blockbuster product – the electronics are coming together, you’ve     ordered some of the longer lead components, and are now planning to build a prototype. You’re excited by the opportunity to rapid prototype some of the more challenging parts using one of the latest 3D printers. Finally, all the parts come together, you assemble the prototype – and it works, meeting/exceeding your expectations! Time to break out the champagne – and you ceremoniously hand the completed design to a contract manufacturer, and at the same time informing your customers on kickstarter that the product will be entering production shortly.

Your CM asks for a meeting and does not sound excited – they inform you that in order to produce the product in the volumes you’re looking for, it will take another 3+ months of engineering and over $100K of NRE to make the product manufacturable. You protest “but we built a prototype, and it worked flawlessly”? It turns out that building a prototype is not a demonstration of manufacturability – it’s a demonstration of the ability to build a prototype. The reality is without manufacturability considerations designed in from the beginning, you’re at significant risk of delays and cost overruns in order to get to a manufacturable product.

We’ve often been called in on a “911” engagement to assist clients who have experienced this situation. Sometimes they’ve used 3D printing technologies to prototype plastic parts, only to find out that those same parts cannot be injection molded. Metal parts that can be CNC machined for a prototype turn out to be too complex and expensive to build in high volume. Some assemblies have too many parts and the labor to assemble those parts is much higher than expected. And some parts have such tight tolerance requirements that the manufacturing yields will be unacceptable low.

So how do you avoid this trap? First, if you’re in the process of selecting a product development firm, ask them to explain/show their DFM process – when does it start, how does it work. If they look at manufacturability later in the process, you run the risk of design iterations further down the line. DFM should be a consideration from day 1 of industrial design – after all, what good is a beautiful design if it can’t be manufactured in the volumes and at the cost you need?

Next, ask them to talk about the skill sets of the team – you’ll want to have engineers with design for manufacturability experience to be part of the team from day 1 – their role is to be the sounding board/voice of reason/reality check for the feasibility of proposed designs from a cost and manufacturability perspective.

Have them discuss their ecosystem of suppliers and manufacturers – the depth and breadth, particularly as it relates to what you’ll likely need for your product – and where that ecosystem is located. For example, if you’re developing a high volume consumer or medical device product, it may be advantageous to utilize off-shore manufacturers. Also discuss when in their process do they start to work with those suppliers – every supplier is somewhat different in their capabilities, strengths/weaknesses, and approach. Some may prefer a design that is more “automated assembly” friendly vs. others – that being the case, you’ll want to design the product towards that end.

Another often overlooked area is designing for serviceability, maintenance, and manufacturing rework – we’ll cover that next time.

About the author

Ken Haven has been CEO of Acorn Product Development since the company’s founding in 1993. Ken has more than 25 years of product development experience including technical leadership roles with NeXT Computer, Attain, Inc., and Hewlett-Packard. He holds MS and BS degrees in mechanical engineering from Cornell University.