About eight years ago, Hypertherm embarked on a mission to revamp the way it designed products. Despite the fact its plasma metal-cutting technology was highly regarded and the market leader in the field, the internal consensus was that product complexity could be reduced and thus made more consistently reliable, and there was an across-the-board campaign to reduce product development and manufacturing costs. Instead of entailing novel engineering tactics or state-of-the-art process change, it was a back-to-basics strategy around design for manufacture and assembly (DFMA) that propelled Hypertherm to meet its goals.

The first step in the redesign program was determining what needed to change. A steering committee with representation from engineering, manufacturing, marketing, and business leadership spent weeks trying to determine what was required from a product standpoint to deliver radical improvements in both product performance and product economics. As a result of that collaboration, the team established aggressive new targets around robustness and reliability in addition to the goal of cutting the parts count and labor costs nearly in half. Once the “what” was clearly defined, the team needed to figure out how to accomplish its competitive new charter. It turned to a robust development approach coupled with DFMA methodology and a software toolset from Boothroyd Dewhurst Inc. and set out on the redesign course.

The robust development approach was essential because Hypertherm’s plasma cutting systems, used by factories and machine shops in shipbuilding, automobile work, construction, and metal fabrication, are exposed to the harshest conditions—from temperature extremes to physical impacts and vibrations. A key design goal was to ensure that any new products would work consistently in all sorts of environmental conditions without requiring customers to do any fine-tuning to ensure reliability. At the same time, the team wanted to configure the products in a manner that would ensure easy serviceability in case of problems. To achieve those stringent quality objectives, the engineering team turned to robustness surrogate testing, an accelerated cycle of design, build, test, break, and fix that mimicked the way customers might break a machine in the field. By performing this process as part of the early design regimen, Hypertherm engineers aimed to avoid the kinds of design miscues that lead to the most common failures and quality issues.

There were a couple of key challenges related to the robust development approach. The first was prioritizing failure modes, since there were thousands of things that could go wrong with any single product yet it was feasible to tackle only a handful of those things in a single design program. There was also the issue of creating the test surrogate. It was easy to break a product quickly, but breaking it in the manner in which it commonly fails in the field was a completely different story. For example, simply accelerating the stress on a cutting torch to achieve a particular failure rate would not provide the appropriate context for optimizing the design; instead, the team had to understand the failure mode in relation to the customer experience and replicate it in that exact fashion. By leveraging internal domain expertise, analytics, and good old-fashioned experimentation, the team was able to zero in on the right failure modes to provide a starting point for the new design. Finally, there was a need to change the engineers’ mind-set away from placing blame on customers for misusing the tool and breaking a “good design” to recognizing that a design might not be robust enough to stand up to the rigors of in-the-field use.

Taking Cost Out of the Equation

In addition to adopting robust design principles, Hypertherm began a campaign to make DFMA an integral part of the product development process in a wholesale effort to reduce its development and manufacturing costs. DFMA, a suite of software, and a development methodology pioneered by Boothroyd Dewhurst guided the engineers through a process to reduce part count and improve assembly with the overall goals of lowering costs and increasing reliability. DFMA would complement already existing lean and Six Sigma quality programs, along with voice-of-the-customer initiatives, as part of Hypertherm’s multiyear effort to bolster product performance, reduce costs, and achieve overall manufacturing efficiencies.

The team started the DFMA journey with one of its simplest plasma cutting products, leveraging the software to evaluate the unit part by part and document the assembly process step by step. From the software, the team generated three key Pareto charts (cost, part count, and assembly time) that established a baseline from which it could measure its success and zero in on the parts and processes in which there was the greatest opportunity for improvement.

Although the approach appears relatively straightforward, the process is quite involved and requires discipline on the part of the engineers. Depending on the complexity of the product being evaluated, it could take a team weeks or even longer to go through the rigorous and detailed exercise of counting every single part and evaluating the assembly strategy—and that was just for the baseline product, not for potential redesign work. Convincing individual engineers that the benefits of the DFMA approach outweigh the commitment it takes to learn and perfect the process has been an ongoing struggle. Hypertherm addressed some of these obstacles by giving the engineering team the tools, time, and training it needed to learn DFMA principles and by making the engineers—not the manufacturing group—responsible for meeting the aggressive cost reduction targets.

The real aha moment came when the engineers finally understood their designs and opened a window into the tangible opportunities for improvement, whether it was eliminating parts redundancies or seeing how a different design approach could eliminate parts such as fasteners and connectors altogether. Once the team bought into DFMA’s power, its members began to see their designs and the whole design process in a completely different light. Nearly eight years into the redesign effort, Hypertherm engineers now perform DFMA as a standard part of the design process and view the goal of parts reduction and design for assembly as their responsibility, not the domain of manufacturing. This has been a major shift for the engineering team and a key enabler for Hypertherm to achieve its aggressive performance and economic goals.

Today, Hypertherm’s metal-cutting products use about half the parts of previous versions, and the company is on course for consistently achieving a 50% cut in production costs. Product performance is up and warranty costs are down, with an 80% decrease per unit from 2002 to 2010. Although lean manufacturing and Six Sigma quality concepts continue to play a key role in Hypertherm’s strategy, it is the engineering team’s back-to-basics makeover around DFMA that has turned out to be the standout initiative fueling the company’s product success.