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Generally speaking, the more thoroughly a manufacturing team develops a design concept, and the more qualified the thought process involved, the more likely the end product's success in the marketplace. That's why most of us who are involved in electronics manufacturing or R&D are familiar with the acronyms DFT, DFM, and DFA. These three stand for Design for Test, Design for Manufacturing, and Design for Assembly. Without delineating the three acronyms into their corresponding disciplines, I would like to add a few more essential design considerations by which most designers live and die.
A product's life starts at conception. That is to say, someone has an idea that may or may not be shared with others. The idea usually blossoms into a stream of thought that includes product features, appearance, budgetary cost estimates, target markets, sales channels, and possibly some early advertising concepts. At any rate, before pen is even put to paper, the creative process has constructed enough information to assess the possible worth or lack thereof of the product under consideration.
I have a patent that started out as a conception based upon a need to perform the same tasks as done by multiple connectors, but only using one smart connector with a smaller footprint. This product came about as a challenge to find a way to use less space while providing simple utility, fewer wires, and, yes, at less cost than the existing connector systems. Fortunately, I had the deep pockets of {complink 3426|Microsoft Corp.} funding my design and experimental efforts. During the development of the new connector system, I found myself having to make several design considerations, in addition to the aforementioned three. Let me list a few that came to my mind:
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Design for rapid market acceptance
Design for legacy product compatibility
Design for simplicity of utility
Design for intuitive application
Design within existing analog/digital technology capabilities
Design for materials availability
Design for longevity and reliability
Design for worst-case operating environments
Design for lowest industry cost
Design for appearance
Design for simultaneous mixed media signal transport
Design for autosensing connect/disconnect
Design for stacking or ganging while maintaining signal isolation
Design for minimal footprint and mounting hardware
What I just described became the 3.5mm multi-contact mini-plug and receptacle now in common use on most of the hand-held MP3/4 players, tablets, and other media players where audio and video signals are being passed through to displays with speakers for viewing and listening at the same time. The IP is not mine. It belongs to Microsoft. I just have the bragging rights.
Now look at the list again and consider the current widespread deployment of this connector system, and you will see that most of the “design for” objectives have been met. The receptacle is virtually the same size as a 3.5mm earphone jack, and the 3.5mm plug end looks almost the same as any 3.5mm audio plug. This one connector pair replaces two Right/Red-Left/White RCA audio jacks and one Composite Video/Yellow RCA jack found on most audio and video products since the 1950s. Look a little closer and you will see more segmentation on the shaft of the plug end… and Eureka! You have the better mousetrap.
Every designer knows that in most cases, every design has some similarity to a previous product. On the list of 14 items, there are generalized design objectives. Each item's emphasis may change, depending on the nature of the product or the market for which it is designed. But to ignore any of these extra “Design For” considerations could bode poorly for the success of the final product. I began by saying the more qualified the thought that goes into a design upfront, the more likely the product will succeed. Consider the list above as food for qualified thought.
Great article, Douglas. I have been involved in working on new designs, but have never really written down all the aspects you need to think about, as you have. It is interesting to look at all the different aspects that need to be considered.
It is great to know who worked on the design of the audio/video plug I have seen so many times! Excellent work on the design, Douglas. It is a simple addition to the common audio plug. Sometimes the easy ideas are the hardest to come by!
@Clairvoyant, Yes. Simple is better most of the time. The prototype connectors were made for me by a comapny in Taiwan (Singatron) and they did a marvellous job of following my lead. I wish they could have gotten some of the benefit but I do not know who really got the first huge orders from Apple, HTC, Samsung, and HP. I regret that after all of their hard work, they probably were not considered an approved supplier by the larger companies. I have a bag of my early prototypes that I just can't see to throw away. There was also a ground sensor in it that told the host equipment if the plug was inserted and a cross connect circuit that would recognize if the connection was from a VCR, DVD, or Stereo receiver. The Sony circuit would detect if the connection was an input or output by the impedence measured as well. It was pretty cool in its early days. Also, I had designed an adpater that would take the composite video out and convert to an S-Video with separate luminance and chrominance outputs characteristic of S-Video signals. I did get $1500 for the patent filing and another $1000 from Microsoft when the patent was approved. Oh I also got an acryllic plaque for my desk.
Great to know that you have designed that connector. Its wonderful to learn that so mnay meticulous thoughts go into designing that connector. We normally follow DFT,DFM and DFA as you mentioned ealrier but the list that you brought in, I guess this is what must also be added in the standards.
Great post, Doughlas. All of these techniques seem to be important considerations that component designers should keep in mind. However, don't you think there will be certain tradeoffs amongst these considerations and you can't really fulfill all of them completely?
For example if you are designing for “lowest industry cost”, it may not be always possible to have the design cater to “longevity and reliability” and “worst-case operating environments”.
Thanks for the post. It is always interesting to hear the perspectives of other designers. Are your “design for” objectives proceduralized in any way or do they vary depending upon the type of project you are working on?
Great post. The “DF” list continues to expand as the markt becomes more competitive and more regulations (I'm thinking environmental) are put in place. As always, and handy list to print out and post somewhere for future reference.
@ Douglas
I tried to critically review the 14 key considerations but couldnt find one without which a product can be successfully completed and also potentially attractive to the customer. As far as your qualified thought idea is concerned, qualification (I am assuming you mean professional/technical qualification from an institution) may be a driving factor in most complication designs but, in the end, it comes down to the creativity of the human brain and practical approach that makes the product successful revenue generator.
Loved the post.
@ taimoorz
However, don't you think there will be certain tradeoffs amongst these considerations and you can't really fulfill all of them completely?
You are right. When you lower the cost, you will have to suffice for a less than ideal solution which might be negatively viewed by the customer. But for a cheap price, customer will be willing to tolerate weaknesses as well. So I guess its about finding the right balance in all 14 considerations.
I read your latest article with interest but must agree with the comments of the earlier reader. It is generally accepted that a cheaprer product is an inferior product. Whilst in some cases costs can be cut without compromising anything, it is not the general rule.
@Flyingscot, you are exactly right. It is not the general rule and so there has to be a deliberate effort called “cost reduction analysis” in place after every initial product release. It is the same players that were under pressure to hit a schedule deadline and so made the most expedient tradeoff of cost vs schedule on many incidental decisions. You have heard of the infamous triangle, cost vs speed vs quality. If you can slow down the speed you can up the other two aspects by providing more time for mor considered thought and resourcing. Maybe the wiz bang chip that cost 3X could be replaced with two chips that cost 2X in their combined cost. This is often the case with electrolytic bulk capacitors for power supply filtering. The design engineer may be able to sub up to three Al-Elec caps with one Poscap , organic polymer, saving both cost and board topography. But, as you say, generally speaking, part-for-part, dropping in a cheaper, exact same function part, can put a product quality and performance at risk. This is where the Component Engineer needs to get the FIT data for reliability and compare proposed part substitutes to the originals. The CE can make significant cost reductions at the component level on almost every design if the focus is to increase or maintain reliability without adding cost.
yes, a value engineering analysis will make it more clear and in turn justify tradeoffs