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88 The PCB Magazine • February 2016 is a reaction." As applied to RCA it means that an action in one area triggers an action in an- other, and another, and so on. By tracing back these actions, you can discover where the prob- lem started and how it manifested into the symptom you're now facing. You'll usually find three basic types of causes: 1. Physical causes: Tangible, material items failed in some way (e.g., a plating rectifier stopped working). 2. Human causes: People did something wrong, or did not do something that was needed. Human causes typically lead to physical causes (e.g., no one performed PM on the rectifier, which led to it failing). 3. System causes: A system, process, or policy that people use to make decisions or do their work is faulty (e.g., the rectifier was not included in the PM system). (Remember my earlier statement that 95% of causes would be directly attributable to a management or system issue?) RCA considers all three types of causes and involves investigating the patterns and trends of negative effects, finding hidden flaws in the system, and discovering specific actions that contributed to the problem. This often means that RCA reveals more than one root cause, each of which needs to be thoroughly vetted through the process. While there may be the occasional Nero Wolfe in a company (or for my younger read- ers, a Gil Grissom), advanced RCA skills are gen- erally a learned behavior. The first investment should be in advanced problem-solving train- ing for (at a minimum) all management on the tools discussed earlier in this column. I like to make the analogy to one of my favorite televi- sion programs, Crime Scene Investigation (the Grissom reference). A quality professional is like a crime scene investigator, and the defect is the crime scene. As illustrated in Figure 2, and dur- ing each episode of CSI, the point is reiterated that the evidence will lead to the origin of the crime. The same is true with root cause analy- sis; where you find one you will always find the other. PCB Steve Williams is the president of The Right Approach Consulting llC. To read past columns, or to contact Williams, click here. root Cause analysis: Csi for the pCb industry The success story of information processing by way of moving elec- trons is slowly coming to an end. The trend towards more and more compact chips constitutes a major challenge for manufacturers, since the increasing miniaturization creates partly unsolv- able physical problems. This is why magnetic spin waves could be the future: They are faster than elec- tronic charge carriers and use less power. Research- ers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and TU Dresden have developed a method for controlling the propagation of these information carriers at the nanolevel in a targeted and simple way; so far, this required a lot of power. They have thus cre- ated a basis for nanocircuits that use spin waves. "our current information pro- cessing is based on electrons," explains Dr. Helmut Schultheiß from the HZDR's Institute of Ion Beam Physics and Materials Re- search. "These charged particles flow through the wires, creating electric currents. Yet in the process they collide with atoms and lose energy, which escapes into the crystal lattice in the form of heat. This means that chips get all the warmer, the closer the elements on them are grouped together. Eventually they fail, because the heat cannot be con- veyed anymore." This is why Schultheiß, head of an Emmy noether Junior Research Group, pursues a dif- ferent approach: information transport via spin waves (magnons). A Highway for Spin Waves