Optimization for manufacturing is a critical, and all-too-often neglected element of the product design cycle. As product development professionals, we often tend to focus on the sexier aspects of a project: defining and validating feature sets, design, prototype development, and functional development. But ignoring manufacturability can lead to sporadic quality issues, delays in initial shipments, COGS that exceed pro-formas, and even complete rebuilds of production tooling.
So what exactly is manufacturing optimization? Manufacturing optimization, when executed properly, results in a final product design that not only provides the features and functions demanded by the market, but is also compatible with the manufacturer’s equipment and processes, at the volumes needed. A critical element to successful manufacturing optimization is engagement of the actual manufacturer that will make the product in the development process.
Focus on optimization for manufacture should start as early as the concept development. In a product that is entering a less-competitive market space, production cost may be less important. In these cases, the feature set should be the primary focus of early stage work, however, it is still important to avoid concept choices that preclude realistic manufacturing plans.
One of the first considerations for a design optimized for production are the materials, components, and technology that are incorporated into the product. For example, plastic injection-molded part design requires attention in several key areas as well as an understanding of what the manufacturer is capable of doing.
Generally, injection molding of plastic works by pressing two sides of a mold together and injecting the plastic under high pressure. However, parts must be designed with appropriate angles on all faces, called a draft, which aids the finished part in releasing from the mold. This draft must be considered across the entire surface of the part with consideration for both sides of the mold, also called tooling.
Features like texture are common on plastic parts. Texture provides more material to the part, slightly boosting its strength as well as adding a nice aesthetic. Even so, texture requires considerations be made in the design for it to be produced correctly. It also adds to the cost of the tooling.
If a part needs overhangs, texture, or other more complicated features, the mold becomes more complicated as well, increasing the overall tooling cost. Despite the added cost, some of these complicated features are necessary in a product.
Here is an example of a project that included manufacturing optimization at the appropriate levels, where our company developed an enterprise dock for handheld PCs.
The first obstacle was that the selected manufacturer was located overseas. To this end, a lead engineer with years of experience and a very strong knowledge of plastic part design was selected to bridge potential communications gaps. This was a risk identified early on and addressed just as early. In the preliminary design review, the manufacturer, having already been selected, was engaged to address potential problems.
In this particular project, it was clear from the concept stage that conventional manufacturing processes would be suitable for the product. The product did need additional features that were key to the value of the project. These features included a retention system that required the use of slides that move perpendicular to the draw direction of the injection mold tooling to produce the part correctly, as well as modifications of the original design to accommodate the slides in the part geometry. This meant changes to the design of the part and higher tooling charges, but changes and cost that were identified early on.
In the example above, three decisions led to smooth and efficient optimization for manufacturing:
- A manufacturer was selected early in the process — in this case, before development even began.
- The development team was led by an individual who provided the design vision, as well as expert knowledge in manufacturing processes.
- In addition to validating use-case and feature set, the development team engaged the manufacturer early and often to ensure the development output was compatible with the specific capabilities and limitations of the manufacturer.
In a second example, manufacturing optimization occurred in a similar way — this time for an IoT-enabled coffee grinder — but at different times to accommodate a Kickstarter campaign, which funded the development.
Kickstarter and similar platforms provide a unique means to validate a concept and generate funding for production, and generally a working prototype is required for a product-centric campaign. The prototype only needs to demonstrate the core functionality of the product. This means manufacturing optimization does not need to be included at all in early-stage development. And the prospect of reducing early-stage development costs by using the platform is an attractive option for emerging businesses.
Even before the development for the grinder project began, the client company and the development team agreed that manufacturing optimization would intentionally be pushed to late-stage development.
This approach to manufacturing optimization would allow for fast development of a prototype incorporating the key functionality for minimal cost. All parties recognized that the net development dollars to a manufacturing-ready product would increase because of this choice. In this case, delaying optimization was a valid business decision, with some risks and some rewards.
Ultimately the Kickstarter campaign was successful and the project was now driven partly by a delivery target date. As with the last example, the manufacturer was engaged early to address potential challenges. And in this round the manufacturer did have specific needs which required significant iteration to the product’s internal geometry and materials.
The product design started to diverge from the prototype that had been developed for the Kickstarter campaign. Many system elements had to be completely redesigned, adding cost and time to the project, as anticipated when the decision was made to forego manufacturing consideration in the initial design. As a result of this planning, none of these extra costs and time came as a surprise to the client, and this is a key aspect of this strategy.
In this example, some of the things that led to higher cost optimization for manufacturing were:
- To minimize time and cost to get to an initial functional prototype, manufacturing optimization was not included in early development.
- The manufacturer selected had specific requirements, which were more expensive to address in late-stage design than they would have been in the early stages. This included the development of custom PCBAs which had not been integrated in earlier iterations.
Unlike the PC dock, the implementation of manufacturing optimization later in the grinder was suitable because of the way it was developed. These examples show two different routes to take to a successful optimization for manufacturing.
To sum up, careful evaluation of manufacturing risk relative to feature sets and function is a starting point that can determine how much to focus on manufacturing optimization in initial development work. Dedicated focus on optimization for manufacture in mid and late development, including direct collaboration with manufacturers, can reduce risk in multiple areas. This strategy for product development will also help avoid unexpected expenses since the stages and conditions that will require additional spending are identified early on.
This article originally appeared in the November/December print issue of Product Design & Development.
Filed Under: Rapid prototyping