Issue link: https://iconnect007.uberflip.com/i/636678
86 The PCB Magazine • February 2016 almost certainly guarantee that the problem will repeat. Although RCA is initially a reactive mechanism, it can become a tool for developing prevention strategies if used properly. Whatever methodology of RCA is used, the system must: •Be interdisciplinary and team-based •Include those most familiar with the situation •Dig deep at each level of cause and effect (The 5 Whys) •Be a process that identifies needed system changes •Be unbiased Drill Deep A good place to start is to make sure that defect classification codes are truly describing the defect, not the symptom. It still amazes me when I go into a shop and review internal scrap data and see generic defect codes such as "elec- trical test short/open" or "undersized hole" for example. I'm pretty sure that the electrical test department did not create the short. Is it an internal or external short? Did incorrect CAM data, a damaged phototool, resist breakdown, a handling scratch, or something else cause the short? To continue, was the undersized hole a result of an engineering error, wrong drill bit, drilling Figure 1: Practical example of the 5 Whys. root Cause analysis: Csi for the pCb industry