DFMA Takes a Back-to-Basics Product Simplification Strategy to Cut Costs

DN Staff

September 7, 2010

9 Min Read
DFMA Takes a Back-to-Basics Product Simplification Strategy to Cut Costs

Sometimes, it's the back-to-basicsstrategies that can deliver the most bang for the buck. Just ask Hypertherm, a manufacturer of plasmametal cutting products. Despite being a leader in its field, the companylaunched a well-orchestrated campaign eight years ago to reduce productdevelopment and manufacturing costs while making its products more consistentlyreliable. Yet it wasn't rapid prototyping, 3-D simulation or any otherstate-of-the-art design tool technology that prepped Hypertherm for itsjourney. Rather, a 30-year-old methodology and little-known toolset from acompany called Boothroyd Dewhurst ledHypertherm on its redesign course, helping the company take a significant chunkout of its part count and production costs.

As part of its product developmentmakeover, Hypertherm tasked engineers with factoring cost targets and assemblystrategies into initial design exploration as opposed to relying onmanufacturing to troubleshoot problem areas later on in the cycle when it isfar more costly and time consuming to initiate changes. By integratingBoothroyd Dewhurst's trademarked Design for Manufacture and Assembly (DFMA)methodology and software into Hypertherm's core product development process,engineers got a jump on the rigorous and often painstaking exercise of countingparts and evaluating designs from a manufacturing and assembly standpoint. Theengineering group's adoption of DFMA was essential to helping Hypertherm closein on its aggressive targets of 50 percent reductions in both part count andproduction costs.

"The 'D' in DFMA stands for design- it's the design engineers that should be doing this work, not manufacturingand not industrial engineers," says Mike Shipulski, Hypertherm's director ofadvanced development. "No matter what your product costs or volumes are, it'stime to take this kind of approach."

Design for the 'ilities'

Pundits in the engineering spacemight argue that this kind of approach is long overdue. Design formanufacturability or design for serviceability are concepts that have beenaround for decades, yet engineering teams, including Hypertherm's, have longstruggled with how to establish the processes and gather the proper informationto give the methodologies their due. "The whole design for the `ilities' hasbeen around for a long time - it's how engineers go about (the process) that'sevolving and changing," says Ken Amann, director of research for CIMdata. "Lots of companies have looked atit for a long time and thought it's too complex or too expensive."

Boothroyd Dewhurst has beenfighting that perception for years, according to President John Gilligan. Themethodology and the software helps estimate the difficulty of assembly, worksto eliminate unnecessary parts and assembly tooling, and facilitates analysisand comparison of the costs of different materials and manufacturing methods inthe design stage, leading engineering groups to create product designs that are"lean from the start," Gilligan says. Fortune 1000 companies like John Deere,Harley Davidson and smaller firms like Hypertherm have leveraged DFMA over theyears to achieve laudable results, including cost reductions of 50 percent,shortened product development cycles in the neighborhood of 45 percent and partcount decreases of nearly half. Despite the magnitude of the improvements,Gilligan admits the methodology is still a tough sell as many companies remainskeptical about the outcomes and are less inclined to commit the time andresources for learning what is admittedly a complex discipline.

"Most companies are pushing to getproduct to market and if they're spending extra time, they're spending it onmaking the product look pretty - not on making it easy to manufacture andassemble," says Gilligan. In many cases, companies are committing that time andmoney to efforts such as lean manufacturing to inject efficiencies and takecost out of the product development equation. "There's a lot of effort on leanmanufacturing to improve the whole process, but with that, you're really onlymaking minor tweaks to the real problems that were introduced back at thedesign stage."

The other main issue is thereisn't a well-defined category of tools to take engineering teams on thisjourney. While Boothroyd counts cost-estimating software among its competition,Gilligan says it's not really an apples to apples comparison since those toolsare often more geared for manufacturing engineers - not design engineers. Theother major differentiator of DFMA is that it combines cost estimating withproduct simplification - an area that the other tools don't support and wherecompanies typically see the most compelling results. More so than othersoftware tools, Gilligan says Boothroyd's main competition is consultants, whoapply their own skills and knowledge of product design and assembly andmanufacturing to redesign products on a project-by-project basis. "It's thedifference between fishing versus teaching you how to fish," he says. "Once aconsultant leaves, their capabilities leave. They're not teaching you how toimprove the products on your own."

Along with consultants and theBoothroyd Dewhurst offering, PLM suites are also starting to add some elementsto address design for assembly and manufacturing concerns, putting theinformation in a usable context and making it widely accessible acrossdifferent functional areas of the business. In that vein, integration withmainstream product development platforms is another barrier for the BoothroydDFMA approach, according to CIMdata's Amann. "People are still trying to figureout, does this really work and how does it fit in," he explains. "Boothroydhasn't done a great job tying into other parts of the PLM world - it's beenmore like a standalone thing."

DFMA at Work

Nevertheless, companies like Hypertherm are seeing somepretty dramatic improvements simply by leveraging this standalone tool set.Hypertherm engineers now routinely perform DFMA as a standard part of thedesign process and they view the goal of parts reduction and design forassembly as their responsibility, not the domain of manufacturing. While thecompany started out small, deploying DFMA on individual projects typically tocreate a baseline for product redesigns, the tool is now regularly deployed onnew designs as well. "We're actually now building two different alphaprototypes of our next product all to help manufacturing determine which iseasier to assemble," says Peter Brahan, Hypertherm's business team leader,automation. "Before, we never would have spent the time or money to do that."

Using the DFMA software, engineers evaluate an individualproduct part by part in addition to documenting the assembly process step bystep. The software helps generate three key Pareto charts (cost, part count andassembly time) which establishes a baseline that allows the team to measure itssuccess, not to mention, identify the parts and processes where there is thegreatest opportunity for improvement.

Using the tool has vastly changed the interaction betweenmanufacturing and engineering. "The teams always worked together, but they werenot closely tied in the design process - mostly in the troubleshooting processwhen the product was in production," Brahan says.

ITT Control Technologieswas a big promoter of lean manufacturing as a means of taking waste out of theproduct development process. Then came DFMA. David Vranson, advancedmanufacturing engineer for ITT's Aerospace Controls division, has beenpracticing DFMA principles since the late 1980s and helped convince the companyto buy the Boothroyd Dewhurst software in 2007 to automate what at the time wasmostly a manual calculation process. When individual divisions began using thetool to improve product designs and eliminate waste, ITT began to see resultsthat weren't possible with just lean manufacturing principles, Vranson says."Nine times out of 10, waste is designed right into the product - it's notsomething that occurs when the design gets to the other side," he says. "That'sthe benefit of DFMA - you look at a design before it's released (tomanufacturing) and get rid of a lot of waste."

Vranson's group, which designs pressure and flow switchesdeployed in aerospace and defense applications and in industrial use, got theirfeet wet with the DFMA software by starting with small projects, using what-ifscenarios to examine small areas of a design. Engineers would experimentputting things together in a different way or integrating parts and utilizingdifferent construction modes to eliminate parts. Even small gains on individualassemblies have big ramifications. Consider a valve assembly project where DFMAanalysis took the number of parts down from 33 to less than half. But it wasn'tjust the part reduction that was a boon. "We were able to manufacture the valveassembly twice as fast; it was two times as fast to put together the new designand we could make twice as many as we could before just by making those changesto the configuration," Vranson explains.

In fact, ease of assembly is perhaps the biggest benefit ofthe DFMA program. "To reduce parts makes it easier to put together and if youlook at what you do across the entire manufacturing enterprise, that's whereyou start to see traction," he says.

Beyond scaling the deployment of DFMA, having top managementsupport of the program is critical to its success. At Whirlpool Corp., company management deemedDFMA as central to the firm's strategy to be the number one cost leader in allof its product categories at each of its price points, according to James D.Bolton, global lead, value engineering and DFMA. Years into the program, DFMAis now part of the company's staged gate process for product development and isused equally to redesign existing products as well as to optimize new productdesigns.

"The fact that the management team bought into this helpedwith a lot of the pushback we got which was typically around time," Boltonsays. "You have to make sure you allocate the right people to the team and berespectful of their time. You don't want to burn them."

Raymond Corp., amaker of electric forklift trucks, learned that same lesson early on. Thecompany has gradually cultivated use of the tool over the years from itsinitial role for helping product designs meet target costs and for negotiatingwith suppliers, to more recently, as a means to make existing and new designsmore efficient to manufacture.

While it's been hard to capture exact savings realized byuse of the tool, Raymond has saved nearly 20 percent on some of its largerprojects, a result of letting the DFMA tool identify areas of improvement,according to Matt Miles, Raymond's supplier quality and development engineer.Today, both manufacturing and engineering are more accepting of DFMA. "We nowhave this internal phrase, `did you DFMA it?,'" Miles says. "It's become anexpected part of the design process."

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