----------------------------------------------------Business Index & ASAP------ TITLE(s): Another victory for QFD. (Reliance Electric Co. Dodge Div.'s use of quality function deployment to redesign products) illustration photograph Summary: Bearing manufacturer Reliance Electric Co Dodge Div used the principles of quality function deployment (QFD) to redesign its SAF mounted-spherical roller bearing. The move was in response to increased competition and customer demands for better products. Thus, Dodge produced the Unified SAF design to take the place of the two noninterchangeable versions. QFD meant having to interview users, designers and manufacturing personnel and ranking their opinions based on statistical methods to guide the developers. Nevertheless, the needs of the end user were prioritized. June 11 1993 v65 n11 DESCRIPTORS: Bearings industry_Product development Product management_Technique FILM NUMBER: 72N 2857 Quality function deployment gets much of the credit for turning an outdated design into what many consider a world-class competitor. Dodge Group of Reliance Electric, a bearing manufacturer in Greenville, S.C., employed principles of QFD in the redesign of a SAF mounted-spherical roller bearing, a type found on conveyors, fans, and countless other machines. Versions of the design have been produced for over 40 years, which made it extremely vulnerable to low-cost, offshore production. Moreover, customers for the part were demanding quicker delivery and customized products as well. Metric versions of the bearing were also becoming popular, and there was increasing demand for higher speed ratings. To stay in the business, Dodge needed a way to counterattack. It hit upon the idea of producing a single design -- a Unified SAF -- that would do the job of its two existing noninterchangeable versions, and solve these other problems as well. The company used QFD to assure both that the new design would be a hit with the customers, and that it addressed complaints about competing products. QFD was literally an exercise as International Product Manager Gene Allison and his engineers hit the road lugging the world's seven most common designs -- at 25 to 30 lb apiece. They quizzed people involved with the SAF about every detail of the bearing, from performance and physical makeup to seals and mounting bolts. These conversations included not only a large variety of users, but SAF distributors, OEM design engineers, and also the maintenance people who serviced it. "One of the things about QFD is it doesn't fit the western way of thinking very well," says Allison. "This isn't a recipe or cookbook method. It's an iterative process where you learn a little, and that suggests some other questions; then you go and learn some more." Baseline, in-depth interviews come first, followed by more narrowly focused discussions on specific aspects of the design. Some responses surprised even these seasoned experts. For example, conventional wisdom is that lighter parts are better; they're both easier to handle and less expensive. So not surprisingly, newer designs weigh less than older versions. "Much to our chagrin," says Allison, "many users rated our oldest design, and a competitor's 1960s-vintage product, highest because they liked the extra material." According to Donald Nisley, senior development engineer, the new housing is stronger and can be modified for special mounting requirements, so users have options that can't be had with older style pillow blocks. The Dodge engineers also went out of their way to find users with particularly demanding requirements. For example, the bearing tends to be the limiting factor in industrial fans. Other components, materials, and manufacturing processes have gotten so sophisticated that today's fans can run faster than the bearings will allow. Improve the bearing and the fan can run faster and move more air in a smaller package. Because a fan is lightly loaded, it has a natural tendency to vibrate, particularly when material builds up on the blades and throws them out of balance. For high speeds with no vibration, very tight tolerances on the housing bore are required. "We found that if we met the requirements of the fan manufacturers," says Allison, "it would make for a better all-around housing for every user." This revelation forced another look at all part tolerances and at the production machinery. Specifying tolerances beyond a machine's capability to hold them is a futile effort. Assimilating all the input from users, designers, and manufacturing personnel involved some tradeoffs. Statistical quality methods helped rank different factors by importance. The results provided guidance when developers had to choose between conflicting priorities. But ultimately, what the end user wanted got precedence. The resulting redesign addressed a number of quality issues. For example, the company had offered what many considered to be an excellent general-purpose dirt and water seal, but some people found it difficult to assemble. The solution: modify the housing groove to accommodate an easy-to-assemble version. And the best seal is no seal. If the shaft needn't extend completely through the housing, Dodge closes one end. Only one seal is needed, not two. This cuts the potential for seal failure in half. A cast closed-end has always been a high-priced special, but "We decided it would be worthwhile to offer it as a standard product at the same price as the open version," says Allison. "We could have charged a premium for that and made more profit, but we'll probably sell more pillow blocks." The cast closed-end is just one example of a special feature in a standard product. Others include a housing designed for grease or circulating-oil lubrication. Other manufacturers offer a small grease fitting and charge extra for a larger oil-lube port, notes Allison. Dodge, in effect, gives away the modification and supplies oversized oil-lube ports. The drain is simply plugged if not needed. Dodge also added a thermocouple location for checking bearing temperature, and the same design handles both the four-bolt mounting style common in the U.S. or the two-bolt standard in Europe. The Unified SAF is interchangeable with all old Dodge SAF designs, and with those of major competitors. This includes bolt pattern, footprint, envelope, and shaft sizes, so it can replace much of what is on the market today. A metric version, with metric threads, plugs, grease fittings, cap bolts, and so on, is built to ISO standards and matches the designs of European competitors. "We put in as many features as we could," says Allison, "because the design is getting closer and closer to the point of sale. What the customer buys is no longer defined well in advance of the sale. And if they need some other option, we can build it promptly, in small, flexible production lots, at a competitive price. One potential customer told us that they prefer to do business with small suppliers, rather than big companies, because delivery worries them. Now we give them most anything they need right out of the box." "Ultimately, the Unified SAF speaks to issues customers are concerned with on every power-transmission product: price, quality, and delivery," says Roller Bearings Product Manager Don Louis. "Now, what used to be a special feature with an extended lead time is standard. And lead time and price are related: readily available products tend to be less expensive than hard-to-get ones. According to Louis, "It ultimately comes back to what every power-transmission customer asks of us: Make it more flexible, cost effective, deliver it faster, and don't make me fool with it." And, notes Allison, even with all the built-in features and more "iron," the Unified SAF costs the same or less than old-style blocks. In part this is due to savings in the foundry and in machining. There are also fewer parts to deal with. One other factor not to be overlooked is the effect on jobs and markets. "We were extremely vulnerable to losing our market to low price, offshore producers," says Allison. The SAF had been a virtual commodity product with a lot of interchangeable parts. If we were going to sell a standard, low-cost product we were going to lose, because we can't make castings competitively with the Far East. We're staking out the area where a guy wants more features in a product that does more, or wants modifications in a few weeks." Dodge's customers seem to agree. Many of the companies who took part in the QFD interviews are now buying up the inventory, forcing Dodge to expand manufacturing capacity for the Unified SAF faster than anticipated. Across-the-board product introduction will be completed by the end of the year.