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Customer-facing processes must be designed to prevent errors and minimize cost of failure. by paul keller
Quality professionals see many costs of quality firsthand. These include our salaries and benefits, the equipment used to measure and analyze quality outcomes, and the waste generated by these processes when they fail to meet requirements. Naturally, many quality cost systems are heavily focused on internal issues, since those are most readily visible to the quality professional. These issues may slow production, forcing rapid response and quick remedy. These issues can quickly become high profile within the organization, particularly in lean and buildto-order systems with minimal inventory to take up the slack in delivery. Quantifying these costs is not trivial, but fairly straightforward nonetheless with minimal assumptions.
Traditional quality systems, circa 1950, relied heavily on inspection and audit functions to detect problems. In these systems, production personnel were strictly responsible for getting product out the door, and the quality personnel served as the gatekeeper to detect issues at two critical points in the process: when product entered the facility from the supplier and when product left the facility post-production.
Fortunately, many organizations heeded W. Edwards Deming's teachings in the 1980s, recognizing the failings of these limited systems, to direct more attention towards prevention and systems analysis. Quality systems were designed to prevent, rather than just detect, issues using tools such as: failure modes and effects analysis (FMEA), which can steer us towards preventing the more critical issues; Poka Yoke or mistake proofing to ensure processes are designed to prevent errors, typically human errors in setup; and statistical process control (SPC) to determine if the process is inherently capable of producing product within the requirements. SPC control charts used by production personnel to verify the process output as it was being generated served to prevent external failures and minimize cost.
While inspections by production personnel still count towards cost of quality expenses, the virtue of the in-process SPC control chart allows smaller samples than would be needed post-production, reducing the overall cost of inspection. Furthermore, a still larger benefit in reducing cost of quality is provided by the earlier detection of process issues, which prevents additional waste (i.e. cost of failure) from this process, as well as that incurred...