From Prototype to Production: Spending Now to Save Later
Investing a Little More Time and Money During the Design and Prototyping Phase Can Save Big in the Long Run
Medical device manufacturers are keenly aware of the importance of getting new products to market as quickly as possible. Product designers are under constant pressure from sales and marketing departments to speed up the development process. But design flaws that are overlooked in the earliest stages can be magnified once the production process begins. By increasing the time and energy that goes into the prototyping phase, device companies can avoid making costly—or even fatal—mistakes.
Prototypes not only are useful for fine-tuning a design, but also can help manufacturers determine the most cost-effective method of production.
This photo represents an ablation tool manufacturered by Smith & Nephew. By using stereolithography prototypes during the design phase, a third to a half of the tooling costs were designed out of the product. Photo courtesy of Vaupell Rapid Solutions and Smith & Nephew.
Manufacturing partners can be a tremendous resource to OEMs during this stage of the process. Howey says he helps customers along the way with everything from helping them determine product tolerances to gaining a better understanding of what’s driving cost.
“The most successful results occur when our customer approaches us right at the concept stages,” said Dan Stefano, general manager for Norman Noble in Cleveland, OH. “At that point, we’ll do a reality check on manufacturability and make recommendations on where they can alter a geometry, for example.”
Once a design is finalized and the product goes into production, it becomes much more difficult to find cost savings. “You really don’t spend a lot of money in the concept phase, but you’re committing all of your downstream costs,” said Steve Ettelson, general manager for Vaupell Rapid Solutions in Hudson, NH. “The more you can nail down and fix during development, the more money you’ll save in overall product life cycle costs.”
The Power of Touch
Perhaps one of the most potent benefits of a prototype is that it brings a design concept to life. A blueprint or a CAD drawing can impart only a limited sense of how the product will look and feel in the real world. Design flaws that may not be noticeable on paper or onscreen often can be obvious once the prototype is in hand.
Ventricular assist device components. Photo courtesy of LaVezzi Precision.
Physical prototypes are especially useful for surgical instruments, which must be designed to feel and behave a certain way in the field. Ric Perry, president of Mack Prototype in Gardner, MA, described a recent project for which his firm developed prototypes of a hammer to be used in hip replacement surgeries. “It was very important for the customer’s consultant doctor that the balance was right, [the hammer] would have a good grip and his hand wouldn’t get fatigued,” he said. “We ended up doing three or four different-sized handles to get the precise feeling they were looking for.”
Creating multiple iterations of a prototype is commonplace today due to the speed in which they can be produced. This allows engineers to refine their designs even further, preventing problems down the line. According to Perry, the prototyping process is down to days and weeks as opposed to months, allowing for more design iterations. “You might prototype something four or five times instead of once to get the best design,” he said.
Of course, the number of iterations required is a function of the complexity of the device. “Some parts are relatively simple, while some have many different features that require tight tolerances,” said Bob Lamson, VP of business development for MicroGroup in Medway, MA. “In these cases, the customer will want to go through several iterations before they get to that end result.”
Communication Is Key
Because a prototype can be built in a variety of ways, it’s important that the OEM’s design team works closely with its manufacturing service provider to determine the best method for that application. The first step is to make sure the supplier fully understands exactly what the product needs to do and how it will be produced. “That helps us direct our customers early in the process towards the changes that support manufacturability,” Ettelson explained.
This overmolded side grips prototype was produced for Fischer Scientific’s Accumet Portable pH meter. Photo courtesy of Mack Prototype.
In some cases, OEMs are reluctant to divulge key information to their manufacturing partner, but not doing so can hinder the process. Ettelson recommends asking as many questions as possible on the front end. He described a project for which a secretive device manufacturer wanted a succession of rapid prototypes for the same part without explaining the specific issue the company was trying to resolve. The product function depended on a certain bubble formation as fluid passed through a cavity. One of his project managers, an aeronautical engineer by training, immediately recognized it as a fluid mechanics problem and knew exactly how to solve it.
“If this question had been brought up earlier, we could have saved the manufacturer the time and expense associated with multiple design iterations,” Ettelson said.
Materials and Methods
If the prototype needs to be completely functional, materials and processes will be thoroughly discussed. “We conduct an interview process with the engineer, who will lay out what the goals are,” said Perry. “If it’s a high-temperature application, for example, we would rule out doing cast urethane and instead look at machining it out of a high-temperature plastic or metal. Or we could possibly make a prototype mold for injection molding.”
Other factors that can dictate the material and method of producing the prototype include whether the part needs to be sterilized or if there’s an area that requires extremely tight tolerances. A lot of the choice depends on the geometry of the part, according to Perry.
High precision surgical components and ventricular assist device components. Photo courtesy of LaVezzi Precision.
For functional prototypes, often it’s critical to produce them in the exact manner the product will be made in a production environment. “If you go to mass production and then find out that you can’t manufacture it the way you had prototyped it, you’ll end up with product launch delays and cost overruns,” said Howey. “Qualities like grain direction, burr and edge condition and component assembly are all factored into how we’re going to prototype it. As a result of our prototyping efforts, we guarantee that the production will be identical.”
Al LaVezzi, president of LaVezzi Precision in Glendale Heights, IL, explained that because his firm produces extremely critical products with very tight tolerances, the steps taken during manufacturing usually can’t be deviated from once the prototypes and the production techniques have been approved. So his company will normally run a “prototype lot” using the same path that will be used on the production run.
Mirroring the ultimate production path also is important for getting an accurate cost analysis. “The customer needs to know exactly how you’re going to make it and how much it will cost in the long run,” LaVezzi said.
Once the design team has narrowed down the prototyping options to one or two processes, the next step is to determine what compromises can be made. “It could be something as simple as allowing the prototype to have a radius on a corner instead of a sharp corner,” said Ettelson. Making such compromises won’t impact the function of the prototype, he noted, but it can save time and money in the process.
Partnering for Success
More cost savings can be achieved by working with the same manufacturing partner for both the prototyping and production phases. Many of these service providers have dedicated prototyping areas in their facilities, which can produce small quantities quickly.
Most often, the machines in these facilities already have been set up to make the prototype, enabling the project to enter production more quickly. “If you’re making a highly complex part with a number of different features, your setup time might not be the most cost-effective portion of the job. But if you run that again, your setup is already done or might just need minor tweaking,” explained MicroGroup’s Lamson. This is especially important to medical device OEMs, for whom process validation is important.
Many contract manufacturers offer a variety of processes under one roof, which can provide improved economies of scale. “Our customers like that they can come to us and cut one purchase order for multiple prototype options, including any metal finishing operations that might be required,” noted Norman Noble’s Stefano. “Once the prototype is nailed down and the customer is satisfied with the results, we’re able to release the product right into production.”
Manufacturing service providers also may use modular tooling to drive both time and cost out of the process. “We can do some quick modifications to the tooling we already have, and we have a dedicated team and systems in place to speed the process,” said Howey.
Sometimes, however, it makes sense to partner with a product design firm. Startup companies especially can benefit from this type of arrangement, because they might not have the design expertise necessary to make a successful product.
“We’ve been able to solve some very difficult engineering problems that deal with size or manufacturing, for example,” explained PADT’s Miller. “We’ve worked on endoscopic devices, which are challenging because of the size requirements. Trying to design a complex mechanism that’s manipulated by wires and has to fit down a throat is very challenging from an engineering and manufacturing perspective.”
Many of PADT’s clients are doctors or small startup companies with a new idea. “They’ll come to us and say, ‘Here’s a procedure that I do, but I really want to do it this way.’ And sometimes their sketches violate several laws of physics. We’ll try to figure out a way to actually get it done,” Miller said.
The Ultimate Benefit
These days, the prototyping phase takes a fraction of the time it once did. Virtual prototyping software as well as advanced equipment and techniques have helped speed this process even further. “Ten years ago, three to five business days was considered a fast turnaround time for a prototype. Now it’s one or two days,” noted Vaupell’s Ettelson.
LaVezzi added that prototyping also is faster and easier than it was in previous years because of today’s multitasking machines. “Today you can produce an extremely complex component on one machine tool that has replaced three or four traditional machines,” he said.
All of these advances not only have improved the product development process, but ultimately have helped create better products. “Better software, cheaper computers and improved materials have combined together to allow the virtual prototyping and the physical prototyping to be much faster and more faithful to the final product,” Miller said.
Everyone wants to compress cycle time and get a product to market faster, but by spending a little extra time and money early on, device manufacturers usually can create the best—and most cost-effective—product possible.