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Who hasn’t finished a project, only to discover that you’d done something wrong and the whole thing would need to be redone? Perhaps you hadn’t checked your work along the way, confident that all would be well in the end. Imagine the costs involved if this scenario were to take place on a commercial production line. The Systems Engineering Approach to things helps ensure this doesn’t happen. Last time we wrapped up our discussion on the Production stage of the systems engineering approach to medical device design, and today we’ll cover the final stage, Utilization. The Utilization stage marks the point at which the medical device has been sold and is in actual use in the marketplace. Despite the fact that the product has at this point undergone many reviews and revisions and a great investment has been made into deciding whether or not to put it into production, changes can still take place in its design. Markets aren’t static, and products may be made to change due to stakeholders’, that is, those with a vested interest, changing requirements, whether those are aimed at further cost reduction, or perhaps to implement innovations to make the product more appealing to end users. Other reasons for change may be initiated by the sales and marketing departments. They keep their fingers on the pulse of consumer trends, and they may want the design modified according to market research and feedback they receive from dealers, service technicians, and end users. For example, the sales staff may have been apprised by end users that the keypad to their electronic muscle stimulating device needs modification. Patients have voiced they would prefer to here a clicking sound when depressing the buttons, in order to receive some auditory feedback. In addition, distributors of the device reported that although the electronic stimulators were functioning as intended, end users didn’t like the feel of the buttons. The lack of tactile feedback often led to confusion because they weren’t sure whether they had depressed the button or not. Another interesting discovery concerning lack of feedback was that product service technicians were reporting premature wearing out of the keypads. Absent the satisfying click sound, users were inclined to push on the pads too strenuously, which drove up warranty service costs. The medical device manufacturer’s stakeholders are always concerned with costs, and increased service costs definitely raise the red flag. Considerations like these typically arise after a medical device enters the Utilization stage. Fortunately, the objective of the systems engineering approach is to ensure that stakeholders’ needs are met in view of ever-changing requirements, even after the device has entered the marketplace. No matter what may happen during the life cycle of a product, the systems engineering approach is used every step of the way, from the Concept stage through to Utilization. That ends our discussion on the systems engineering approach to medical device design. Next time we’ll begin unraveling some of the mysteries and misconceptions behind patenting inventions. ___________________________________________
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Posts Tagged ‘cost reduction’
Systems Engineering In Medical Device Design – Production, Part 4
Sunday, March 17th, 2013|
Did you know that from the early days of the Industrial Revolution until well into the 20th Century it was common practice for all aspects of a product to be built entirely under one roof? For example, a wheelchair manufacturer in the 1890s would buy the various raw materials needed to construct component parts, everything from bars of steel and wooden boards to rattan stalks and gum rubber, then produce every part of the wheelchair in one facility. Items as diverse as chair frames, footrests, wicker seat cushions, springs, wheel rims and spokes, and tires would all be constructed from the raw materials purchased, then assembled into the finished product. Doesn’t sound like an efficient process to you? Henry Ford didn’t think so either. In fact, he is credited with pioneering mass production in manufacturing when he observed during the production process of his line of automobiles that inefficiencies abounded. Inefficiencies in manufacturing are common, as they are in everyday life. Last time we saw how robots, i.e., the introduction of industrial automation, can be used during the Production stage of our systems engineering approach to medical device design to increase efficiency and reduce manufacturing costs. Today we’ll take a look at another inefficient practice, along with its solution. Returning to our wheelchair manufacturer, the problems associated with manufacturing and assembling all aspects of a product are many. At the top of the list is the substantial cash outlay that’s required to buy and maintain a huge factory complex and all the specialized equipment required to make each and every part. In addition, there’s the ongoing expense of employing and training employees needed to fabricate each component. In other words, the wheelchair factory has a lot of fixed overhead expense to carry, and the more overhead there is, the more expensive the end product. Expenses such as these are almost always passed on to the buyer. The solution? Outsourcing. That is, using outside manufacturers to produce many, perhaps even all, of the component parts. Then our wheelchair manufacturer would simply assemble the purchased parts into the finished product, resulting in lower manufacturing costs and higher profits. The benefits of outsourcing were widely recognized in the decades following World War II, when the post-war economy was booming and demand for consumer goods increased dramatically. That ends our look at the Production stage. Next time we’ll move on to the Utilization stage to see how the systems engineering approach is put into play once the medical device has been introduced into the marketplace. ___________________________________________
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Systems Engineering In Medical Device Design – Production, Part 3
Sunday, March 10th, 2013| When I was a kid I had a toy robot that captured my attention like no other toy. I thought it was so cool to have something animated that looked both humanoid and machine-like at the same time. It couldn’t do much, just walk in a stiff, jerky way and move its arms up and down, but that was enough to keep me fascinated.
Today’s generation of robots do not often take on the humanoid form, but they’re capable of so much more. Robots on assembly lines perform a variety of tasks like welding and placing electronic components on circuit boards, and they do it much more quickly and accurately than any human could, so they’re often employed in manufacturing. We’ve been discussing the Production stage of the systems engineering approach to medical device design. We learned that within the manufacturing process there are often opportunities for cost reduction, and today we’ll see how robots can be used to reach those goals. Last week we presented a sample scenario involving the manufacture of a percussion therapy device. In their quest to reduce manufacturing costs, engineers identified bottlenecks along the assembly line which led to idle worker time and the inability to keep up with orders. In addition to these production woes, it was discovered that the tedious, repetitive manual labor that occurred at each bottleneck created opportunities for assembly mistakes. As many as 30 devices per day were being rejected by quality control inspectors due to issues such as faulty wiring and improper parts usage. This led to expensive rework to correct mistakes. After further evaluation, design engineers determine that bottlenecks can be eliminated by installing automated assembly equipment in the three distinct assembly stages represented on the line, those involving wiring harnesses, printed circuit boards, and the motor drive mechanism. The potential for human error is high during many facets of manufacturing, and this can be minimized or eliminated through the use of robots, that is to say, mechanized equipment capable of automatically performing a complex series of specific tasks. These robots never tire of performing tedious, repetitive work, and their efficiency is unparalleled. Their introduction at key junctures on the assembly line has benefits across the manufacturing process, enabling workers to keep continuously busy and reducing the incidence of human error. The introduction of robotics is known as industrial automation. Robots efficiently increase manufacturing speed, and along with it profits, so their introduction more than compensates for the investment costs associated with purchasing them. Next time we’ll continue our look at the Production stage to discover another way that systems engineering can simplifying the assembly process, by eliminating some functions altogether. ___________________________________________
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Systems Engineering In Medical Device Design – Production, Part 2
Sunday, March 3rd, 2013| Last time we began our look at the Production stage of systems engineering. We learned that cost reduction is a frequent component of this stage due to market fluctuations and ongoing stakeholder requirements to cut costs, and that savings can be made through substitution of plastic for metal parts. In fact, there are many faces to cost reduction. We’ll explore another of those today.
Cost reduction isn’t limited to material expense. Within the manufacturing process itself there are often ample opportunities for cost reduction. As an example let’s say we’re manufacturing a medical device known as a percussion therapy device on an assembly line employing 21 workers over three shifts. This line assembles 300 devices per day at a combined material and labor cost of $2,100 per unit. Percussion therapy devices are frequently used within the medical setting as they perform the very important function of helping to dislodge mucous from patients’ lungs. As such, they are in high demand and the market for them competitive. In our scenario some stakeholders in the device’s manufacture, in this case sales and marketing managers, specify that a cost reduction of $200 per device is necessary to avoid losing ground to competitors. In response to this directive, design engineers take a fresh look at the assembly process. They identified several bottlenecks at key junctures during which manual labor is involved. They note that due to the painstaking work required at these stages, production is slowed. Assembly lines operate dynamically, meaning any disturbance in the flow of activities has vast repercussions down the line. Bottlenecks in flow slow production lines, just as they do traffic on key arteries. A tie-up on assembly lines equates to production delays, and these may lead to difficulty in filling customer orders. Impatient customers have been known to turn to competitors when their orders aren’t filled, and this translates to lost revenue to our manufacturer. Next week we’ll see what manufacturing changes are employed to solve identified problems, and we’ll see how man’s best friend is not a dog, but a robot. ___________________________________________
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Systems Engineering In Medical Device Design – Production, Part 1
Sunday, February 24th, 2013| Done any remodeling lately? If you have, you’ve been faced with countless choices regarding design and materials. Even a relatively simple decision such as putting in hardwood flooring requires many considerations. What type of wood? What grade? How about the stain? Should it be factory stained and sealed, or should the flooring be installed by single board, then stained and sealed in place? Ultimately, your decision is based on your requirements with regards to cost, durability, and personal style.
Now imagine the decision making process that is required to produce a medical device. We’ve been discussing this complex process during our series on medical device design utilizing the systems engineering approach, a systemized approach to product development, design, and manufacture that is used within many manufacturing arenas. Its objective is to relate the requirements for manufacture, regulatory compliance, sale, use, and maintenance of the product to specific design criteria for functionality, durability, and safety. By doing so, the systems engineering approach ensures that the product meets or exceeds all requirements. Last time we wrapped up our discussion on the Development stage of systems engineering by discussing field testing of medical devices assembled during Preproduction. Problems encountered during this phase result in a comprehensive review of the device design and instructions. When all issues have been resolved, things move on to the manufacturing phase and full commercial production. During the Production stage, engineers make continual assessments of the manufacturing process and ongoing adjustments are made to the device design and manufacturing protocol as necessary, this due primarily to changing stakeholder requirements regarding cost reduction. In the competitive marketplace, cost reduction is a never-ending quest to maintain profitability in view of changing economic and market conditions, and this must be done without compromising the quality, safety, and effectiveness of the device. For example, suppose a medical diagnostic imaging machine was designed to be fitted with a machined metal gear in one of its mechanisms. The manufacturer specifies that a $10 decrease must be made in production costs so it can continue to be sold at an acceptable profit margin. After reviewing the design, engineers discover that substitution of a molded plastic gear would reduce manufacturing cost per machine by $12. This is a common scenario, as plastic parts are often substituted for metal to save on cost. Plastic versus metal? How can that be an acceptable swap? In many cases, it can be. Mechanical stressors are analyzed, and if the plastic gears meet durability requirements as well as their metal counterpart, they are substituted. During the Preproduction phase these plastic gears are used in both lab and field testing, where they are put through the rigors of real world use. If they perform acceptably, they are made a permanent part of the device’s design and used in commercial production. Next time we’ll continue our look at the Production stage to discover another way that systems engineering can facilitate cost reduction to meet stakeholder requirements. ___________________________________________
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