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Good designs brewing at Access Business Group

Boothroyd Dewhurst : 30 September, 2006  (New Product)
Access Business Group (Ada, Michigan) develops, manufactures, and distributes a comprehensive range of durable goods, including patented water treatment and air filtration systems, and an award-winning coffee maker. Access has emerged as a leader in water filtration products, using special carbon and ultraviolet light technology for optimal health and taste benefits.
The National Sanitation Foundation International commends the high performance of Access filtration systems, and the Water Quality Association awarded Access with its Gold Seal in 2000. A division of Alticor, Access has over 40 years of experience in product design and development.

Two years ago, Access Business Group wanted to produce a high-end coffee maker to support a line of water filters and gourmet coffees. The resulting Kahve Coffee Maker is the only machine of its kind endorsed by The Society of Specialty Coffee Association, the largest trade group for the coffee industry. Through several design iterations, using special software, Access successfully reduced parts count, assembly time, and cost. Distinctive design features of the Kahve Coffee Maker include a spinning brew basket and closely controlled water temperature. Special attention to temperature control and uniform coffee saturation achieves the taste benefits of maximum coffee extraction with pure water. 'Coffee drinkers will purchase high quality coffee beans, but they now want sophisticated coffee makers to produce the richest possible taste,' says Rick Good, research scientist and process manager at Access Business Group.

'Our main challenge, beyond creating flavor-eliciting features, was to design the coffee maker to be a streamlined, efficient machine,' says Good. Access Business Group achieved its objectives with help from Design for Manufacture and Assembly software from Boothroyd Dewhurst, Inc. of Wakefield, Rhode Island. DFMA software provides a systematic means of examining the structural efficiency and overall manufacturability of a product. Design for Assembly analysis helps engineers assess the contribution of each part as it relates to the cost efficiency and functionality of the whole design. Design for Manufacture analysis enables designers and concurrent engineering teams to anticipate manufacturing costs early and to make informed trade-offs regarding the costs of producing multifunctional, streamlined designs.

Kahve Coffee Maker
The Kahve Coffee Maker, produced by Access Business Group, a leader in water treatment and filtration systems. Using Boothroyd Dewhurst's DFMA software, Access evaluated alternative designs and lowered the number of necessary parts from 122 to 81, saving material and assembly costs.

DFMA Software Helps Access Improve Kahve Design
A major goal of DFMA analysis is to determine the minimum number of parts necessary in a design. For Access Business Group it is also integral to the ITM (Ideas to Market) process for benchmarking and brainstorming on issues related to product features and capabilities, manufacturability, and public health.

At Access, use of DFMA typically begins at the preliminary bill of materials stage to establish a basis for comparing further revisions. For some durable goods, such as the Kahve coffee maker, Access benchmarked existing units from Krupps and Braun. These represented established competitors' designs with price points comparable to the Kahve. DFMA analysis is an iterative process at Access, applied at the end of each design revision. 'We use DFMA aggressively to challenge the design to become ever more efficient,' says Good. As each revision to the bill of materials progresses to the release of product development, there is a significant change, followed by a review and comparison with the last design.

The Kahve coffee maker requires a motor to turn the spinning brew basket. Initially the motor was at the base of the machine with an elaborate pivot and holding system that extended up through the unit. This motor-powered holding system would turn an O-ring under the outer rim of the brew basket, spinning it quickly. Once a brewing cycle began, the spinning brew basket would render uniform coffee extraction. Unfortunately, the large size of the motor required made the planned unit appear bulky, which would not have supported the design team's emphasis on light elegance. DFMA helped reduce the part count of the motor assembly and led designers to reposition the motor higher on the machine, closer to the power destination. As a result, designers found that they could use a smaller Mabuchi motor that needs less power and maintains the sleek lines most consumers expect from luxury design. 'The software systematically challenges engineering assumptions. In this case we were freed from a basic misconception that a motor had to be positioned at the base of the unit,' says Good.

Access applied three rounds of DFMA to the coffee maker design. The machine is a combination of original design and purchased components. The first round at the concept stage tested a preliminary bill of materials, the second round occurred in mid-product development after the motor was raised. The third round fine-tuned the design. The DFA software provides an objective rating of the design, called an index, that engineering teams use to measure development. The index number rises as the design's assembly times and cost are lowered, and parts are consolidated or omitted. This table indicates how DFMA helped reduce part count, cost and assembly time of the Kahve coffee maker:

Water Filtration Design Flows through DFMA
Access engineers recognized that using specially filtered, and temperature controlled water in a coffee maker was one clear way towards better coffee. Using filtered water maximizes the Kahve's taste-enhancing capabilities. Water filtration systems are a core competency at Access, including filters installed on countertops or below sinks. Most Access water filters use carbon activated filtration, and recent technology adds UV-light disinfection for increased cleaning efficiency.

The carbon-block water filter works in four steps. Untreated water flows into the outer filter chamber. First, a non-woven pre-filter removes large particulates. Pre-filtered water passes into a second area, closer to the filter core, where another non-woven pre-filter extracts smaller particulates, such as clay and sediments. Next, the central carbon-block filter removes very fine particulates, parasites, lead, and certain chemical contaminants. Carbon, pre-activated with oxidizing gases at very high temperatures, attracts and binds certain chemicals as water passes through the porous carbon block. The filter surface may interact chemically with organic molecules, and electrical forces may result in an ion exchange or adsorption of the contaminant. This filter removes many specific organic contaminants with relatively large molecules, depending on pore size and distribution. After the water is carbon treated, it flows through a tube to exit the filtration system.

eSpring water filtration system
This carbon-block water filter removes specific organic contaminants. A pre-filter removes large particulates before water passes through a second pre-filter. The porous carbon block attracts and binds parasites, lead, and other contaminants. Boothroyd Dewhurst's DFMA software helped Access Business Group reduce part count by 20 percent and assembly time by 35 percent.

Some filters also contain a UV-light. When ultraviolet rays penetrate water it destroys other harmful microorganisms like e-coli, cholera, and tuberculosis. The UV-light sterilizes water by scrambling the DNA structure of exposed microbes. This kills the cell and the microbe is not longer a threat. The ultraviolet light disinfection process kills unwanted bacteria and virus organisms to a 99.9% purity level.

Good points out that beyond a demand for the best possible flavor, 'The American consumer is increasingly concerned about relatively high water bacteria and contaminant levels.' Emphasizing taste and health, Access keeps the pore size of its carbon water filter small, to remove the highest amount of particles. For similar reasons, the company stresses reliability of the sensor bulb that lights when a filter needs replacement. Standards of protection for public water sources vary greatly from one nation to the next. This must be taken into consideration for design and manufacture on an international scale. 'China is a major growth sector, with high levels of large particles in the water,' says Good. 'Therefore, Access currently uses DFMA to benchmark filtration systems and add a pre-filter that will remove large particles without clogging the unit.'

Access used DFMA to reduce parts count and assembly time of their filter design for combined carbon and UV-light water treatment. DFMA results suggested that the two-piece carbon block holder, called the pressure vessel, be combined into one piece. Designers wanted to integrate the UV-lamp using inductive coupling, which is wireless. This would also eliminate connectors and lead wires to the UV-lamp sub-assembly. The lamp's primary and secondary coils, positioned like a smaller donut inside a larger donut, create a wireless field of electric activity that powers the lamp. The following table shows results from five rounds of DFMA that improved the filtration system.

Water Filter DFMA Round 1 DFMA Round 5 DFMA Results
Access retains DFMA benchmarks of all prior products for future comparison. The company is currently developing a new unit for the U.S. market. As a next generation, it will be compared to the 'parent' product. 'We can look at outside competitors, but we view ourselves as our own competition,' says Good.

Is Outsourcing Design Counterproductive?
Many other companies still rely on outsourcing design, but Access Business Group is bringing design, prototyping, and manufacturing capabilities in-house. 'Centralizing these processes retains creative direction, and control of cost and quality,' says Good. 'The trend at Access is to avoid the dangers of excessive outsourcing of design and manufacture. To achieve success, our company had to avoid becoming facilitators and manufacturing coordinators.'

Access Business Group purchased many intellectual property rights from contractors in order to consolidate company efforts and maximize control. Internalizing design and product development meant that teams had to become cross-functional. A typical project group has a program manager with a team charter. The charter ensures representation from each department. Depending on the project, there may be a team member from electrical resources, mechanical engineering, and chemical engineering. The group also includes quality assurance and manufacturing representatives. Good notes that 'Superior design is a function of analysis, marketing specifications, and other factors. Bringing the design process in-house allows us to apply DFA to all the design elements influencing product cost and performance.'

Tasteful Design Is Rewarded
The Society of Specialty Coffee Association, the largest coffee trade organization, officially recognizes the Kahve Coffee Maker for having the highest measured uniformity of extraction rating for any gravity-drip coffee maker. The SCAA identifies certain criteria for improving coffee taste, including uniform coffee extraction, clean water, and temperature control. The spinning brew basket manages contact time and maximizes coffee extraction. Pure water is achieved with double pre-filtration and the special activated carbon filtration technology, which received the highest rating from the National Sanitation Foundation. The Kahve Coffee Maker is the only brewing machine ever to be formally endorsed by SCAA.

Initially, the Kahve was developed as a luxury coffee maker to use with advanced water filtration systems and to boost sales of a specific gourmet coffee line. Having fulfilled its supportive role, the Kahve Coffee Maker design is now available to manufacturers. 'The design quality we achieved with DFMA, a high consumer demand for gourmet coffee, and our unique SCAA endorsement make the Kahve Coffee Maker extremely marketable,' says Good.

Design analysis software helps instrument builder develop a new product in time to capture a healthy share of the market

Whenever a window of opportunity opens for introducing a new scientific instrument, MDS SCIEX (Concord, Ontario) leaps through it confidently. Such was the case a few years ago when the opportunity arose to develop a hybrid mass spectrometer combining time-of-flight technology with conventional quadrupole designs. The new design had been gaining favor among chemists because it widened the range of compounds that laboratories could analyze and identify, from naming simple compounds to distinguishing differences among molecules as large and complex as DNA.

Management at MDS SCIEX, a division of MDS Inc. and a leading manufacturer of quadrupole mass spectrometers, knew it had to act fast to capture a healthy share of this new hybrid market before the window closed. The company had only 12 to 15 months to bring to market a commercial product that chemists could use out of the box. In early 1998, management set into motion the QSTAR project, the largest product development program in the company’s 25-year history. The 75-member development team transformed a breadboard developed by scientists in the research laboratory into a high-quality, cost-competitive, shippable product that did not require onsite assembly and a technician to install.

Achieving these goals was an enormous challenge because breadboards are essentially science experiments for proving concepts and are much too complex to build and use. “Each one is custom assembled and tweaked,” says George Valaitis, manager, mechanical engineering. “The scientists file parts to fit and wire pieces together.” Consequently, teams of design and manufacturing engineers must work with the scientists to convert breadboards into commercial products. Even after simplification, the QSTAR contained 8,000 parts, 1,500 of which are unique.

Coordinating the large number of people involved in bringing this complex instrument to market required a highly disciplined approach. The engineering team used Design for Assembly software, part of the Design for Manufacture and Assembly series of software from Boothroyd Dewhurst, Inc. (Wakefield, R.I.). In addition, the team relied upon the Six Thinking Hats brainstorming technique developed by Dr. Edward de Bono. “The DFA software was a catalyst to stimulate discussion and to guide technical analysis of the design,” says Valaitis. “The Six Hats method kept our discussions focused so the design work would stay on schedule.”

Flight tube
View of the flight tube of the QSTAR triple quadrupole mass spectrometer. MDS SCIEX used Design for Assembly software from Boothroyd Dewhurst, Inc., to optimize the design of modular components for the flight tube, including the ion detector, the accelerator, and the reflector subassembly.

Beyond the Breadboard
QSTAR mass spectrometers are large, sophisticated instruments produced in low volumes. The manufacturing team recognized that ease of assembly would largely determine the cost, manufacturing efficiency, and field performance for the product. As originally constructed, the breadboard was difficult to assemble and needed days of testing and tweaking to find its sweet spot for performance.

Redesigning the QSTAR so it had as few components as practical, and devising components that were self-jigging and self-locating, were important goals for simplifying the breadboard. The QSTAR engineers used DFA software to analyze the existing design and to spark innovative ways to consolidate parts and eliminate assembly difficulties. After the DFA software guided the design teams through a round of improvements, the version of QSTAR that went into production achieved tight mechanical tolerances without requiring post-assembly adjustments.

Another goal was to stabilize the instrument and its modules for shipping. Because the scientists who developed the breadboard exploited gravity to hold some components together, the device could not withstand any side loads. Moreover, some of the major subassemblies in the breadboard were fragile. Precision components were stacked on top of each other like building blocks. To add support and improve the tolerances, the new design called for hanging components and modules from a supporting structure, rather than stacking them. Tests of the redesigned instrument showed it could withstand side loads as great as 8 g.

One of the most important assemblies designed with the aid of DFA software was the flight tube, an added component that allows the traditional quadrupole apparatus to generate orders of magnitude more data about the substance being tested. After an ionization process strips an electron from each molecule and the newly charged particles enter a vacuum chamber, two sets of precisely machined and coated dipoles sets the particles into motion, sending them through a series of filters and into a uniform stream. A particle accelerator shoots the stream of ions down the flight tube toward a series of coils that reflects them back to an ion detector. Because heavier particles take longer to bounce back, the device can systematically calculate the atomic mass of particles and identify the substance.

“We answered the questions in the DFA software one by one,” says mechanical engineer Goran Marunic, a member of the flight tube development team. “The questions prompted a series of discussions about part count and assembly efficiency. Working closely with manufacturing engineering, we kept the design modular, aiming for more manageable development and better assembly and serviceability. We divided the design logically into subassemblies, each of which had its own bill of materials.”

Carrying good design-for-assembly practices even further, Marunic and his team also designed the subassemblies of the flight tube to be self-fixturing and self-centering modules. The ion detector and accelerator assemblies fit only one way, so assembly mechanics can insert them correctly every time and not have to spend time adjusting alignments.

Top of the flight tube
View of the top of the flight tube. The ion detector and accelerator assemblies were designed to be self-locating so they could be inserted into the vacuum chamber in only one way. The modular nature of the flight tube design aids in shipping and servicing the QSTAR.

Focus on the Reflector
The reflector subassembly was a critical module in the flight tube and the most fragile component in the breadboard. Consequently, the reflector subassembly was subjected to several analyses with the DFA software. “We debated its design right up until we finished conceptualizing the product,” recalls Marunic. “Marketing did not want to have to ship it separately and assemble it in the field. Initially, we analyzed the breadboard instrument with the DFA software. After thinking about the results and improving the reflector module, we used the software again to validate our concepts.”

One problem the software flagged was the insulation separating a series of metal rings that line the reflector section of the flight tube. In the breadboard, ceramic balls were used as spacers between each metal ring to regulate the -5 to +1 kV potential across the assembly. “Although the balls insulated the parts and made the rings self-centering, they were not shippable,” says Marunic. “They crumbled when subjected to vibration or a load from impact. So during design, we moved from ceramic balls to flat ceramic spacers to sheets of Kapton.” The Kapton sheets cut cost tremendously and led to a rugged assembly.

The DFA software also flagged the number of fasteners connecting the stack of resistors and metal rings. In the initial concept, the scientists had mounted each of the 32 resistors in the breadboard with four screws, which contributed heavily toward the 8-hour assembly time. “As an alternative, we designed a connection that allows a technician to press the resistors into the metal part,” says Marunic. “Because they require no screwing, they’re quick to assemble and easy to replace.”

In the end, the QSTAR team designed a reflector subassembly that can be put together in only 45 minutes and can be removed and serviced without disrupting the rest of the instrument. Whereas the breadboard reflector contained 289 parts with 26 unique components, the final reflector module contains 144 parts with 21 unique components. Only three screws and three nuts hold all 144 parts together.

Better parallelism was another important result. “Parallelism was a parameter we had to control closely to meet the marketing department’s performance requirements,” reports Marunic. “If the flight tube were not parallel, then one side of the relatively wide particle beam traveling through it would reach the detector before the other.” Parallelism in the first two assembled prototypes of the reflector was measured at 0.00043 inches and 0.00063 inches, more than an order of magnitude tighter than the 0.002 inches achieved in the breadboard and the goal of 0.00125 inches set for the final commercial version. What makes this feat of accuracy even more phenomenal is the fact that tolerances were measured over a stack of 144 parts.

Reflector subassembly
View of the reflector subassembly, a stack of resistors and metal rings that constitutes an important component of the flight tube. Using DFA software to analyze the design, the QSTAR team reduced the part count for the final assembly from 289 to 144. They also reduced the number of unique parts from 26 to 21. In the original breadboard design, each of the 32 resistors were mounted with four screws, an assembly process that took hours to accomplish. In the final design, press-in resistors require no separate fasteners.

Quality Control Plan Pays Off
From the beginning, the QSTAR engineers followed design practices that helped them avoid quality control and troubleshooting problems in manufacturing. Key elements of their strategy were to design the instrument in modules and to identify measurable parameters that would indicate the instrument’s ability to perform in the field.

Parallelism of the flight tube assembly is one such parameter. Because the offset voltage across the flight tube is a function of how parallel the tube is, the QSTAR development team decided that measuring the voltage would be a quick quality control check of parallelism. They specified a tolerance of –31 V to +7 V for the offset voltage. After assembly, the instrument goes to a final testing station, and an inspector measures the offset voltage and other parameters and plots them on a control chart.

If offset voltages or other values wander out of tolerance, a team of investigators can exploit the modular design of the QSTAR to find the source of the problem. “By designing the critical components and subassemblies as modules, we can replace them to see which module influenced the performance of the machine,” explains Marunic. Meanwhile, the ability to swap subassemblies allows production to rework only the module in question, rather than tying up an entire assembly bay while technicians isolate and correct the problem.

In August 2000, after production of an improved generation of the product was well underway, a problem surfaced that put this scheme to the test. Several offset voltage measurements were suddenly at or near the lower tolerance limit. Although the instrument passed inspection, the trend indicated a problem somewhere in the manufacturing process. “Because of the modular design, we were able to isolate the subassemblies that were degrading the performance of the machine and trace the problem to a particular vendor,” says Marunic. In the midst of changing ownership, one machine shop had stopped checking some part dimensions specified in the original certification.

“We were able to find the problem and correct it quite quickly without disrupting production,” notes Marunic. Considering that QSTAR mass spectrometers sell for $300,000 to $450,000 each, designing in the flexibility to troubleshoot and correct problems without halting production saved a lot of money.

Design for assembly practices saved money in other ways, too. By reducing the part count, QSTAR engineers cut materials costs by $35,000 per unit and reduced opportunities for design and manufacturing errors. Marunic estimates that engineering corrections made per part for the QSTAR amounted to less than half those made for three of the company’s earlier mass spectrometers.

Most importantly, DFA helped shorten the development cycle by 20 percent. MDS SCIEX management calculates that getting to market in 14 months increased revenue by $20 million and allowed the QSTAR to capture one-fifth of the global market in the first year of sales. For a company that plans to continue leaping through windows of opportunity, that’s a welcome landing.
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