Issue link: https://iconnect007.uberflip.com/i/857644
92 The PCB Magazine • August 2017 tools/materials/supplies they used to do it, and the conditions under which they did it are just a few bits of information that should be known and readily available to someone investigating a process that has produced some bad widgets. For example, let's say our widget is a sealed unit that has a printed circuit assembly inside that is sensitive to moisture. The unit itself has a cover on it that is attached via screws with a gasket for sealing purposes. The client is experi- encing failure of the widget when it is installed in a humid/wet environment. As a result of test- ing that would have been performed to investi- gate the issue, let's say that the root cause of the field failures was determined to be water/mois- ture ingress around the cover. From here, the owner of the widget would likely go to the manufacturing line to investi- gate the cover attach process. So, at this point, the more information that the investigator can get about that step in the process the better. A simple bit of information would obviously be to know which operator installed the screws and which screwdriver they used, but that might only be the tip of the iceberg in respect to what information could be known. Other examples of bits of information that would likely be of interest in this situation would be…How much torque was applied to the screws? What is the material (lot) traceability of the cover plate? What is the material (lot) traceability of the gas- ket? What is the material (lot) traceability of the screw? What were the environmental con- ditions on the line when the unit was sealed? Those are just a few of the questions that the investigator might ask to try to solve the is- sue at hand. Thus, having complete traceabili- ty of your process will allow for easy dissemina- tion of the needed information. Who knows… maybe the solution is as simple as a bad lot of gaskets? Or, maybe, the torque setting on the screwdriver was incorrect from 9–11 a.m. on a given Tuesday? These are all very plausible an- swers to our example, but finding these answers would be impossible if the traceability informa- tion wasn't being recorded and/or stored. Traceability is not designed to be a blame game, although that does unfortunately some- times happen given the world we all live in. From an analytical vantage point, establish- ing a mentality in which everyone understands that traceability allows for quicker and more efficient problem solving and troubleshoot- ing when/if things go awry is really the great- er theme. If you knew it was Professor Plum in the library with the candlestick from the very beginning….wouldn't the game be much easi- er to play? PCB Keith M. Sellers is operations manager with NTS in Baltimore, Maryland. To read past columns or to contact Sellers, click here. PROFESSOR PLUM IN THE LIBRARY WITH THE CANDLESTICK…RIGHT? Quantum computers of the future hold prom- ise for solving complex problems, like factor- ing large numbers, exponentially more quickly than ordinary computers, allowing them to break codes in commonly used cryptography systems. Other applications for quantum computers in- clude solving complicated chemistry problems in- volving the mechanics of molecules. But exactly what types of applications will be best for quan- tum computers is still an open question. In a new Caltech study, accepted by the Insti- tute of Electrical and Electronics Engineers (IEEE) 2017 Symposium on Foundations of Comput- er Science, researchers have demonstrated that quantum computing could be useful for speed- ing up the solutions to "semidefinite programs," a widely used class of optimization problems. These programs include so-called linear programs, which are used, for example, when a company wants to minimize the risk of its investment port- folio or when an airline wants to efficiently assign crews to its flights. Designing Computer Software of the Future