tgvantagepoint

Sensitivity Analysis are what-if analysis that are used to check for the most effective permutation of the independent variables, one that would yield the best possible impact on the dependent variable, under a certain set of assumptions. It is to test the behavior of Y for each change in X and arrive at the best scenario. Now, one of most powerful tool for ‘Root Cause Analysis’ is FMEA. I call it most powerful by the simple virtue of being most proactive of the tools as opposed to a more reactive one, say ‘5 Whys’. Now while the experts are expected to take a lot of care in determining RPN while performing FMEA, and that involves active participation of the SMEs, inputs being provided on Severity, Occurrence and Detection need be independent of one another, use of actual data, et al, there is still subjectivity involved. Sensitivity analysis could help to test the marginal relationship between the RPN and the independent variables (Severity, Occurrence, Detection), and see how a marginal change in one of these would impact the RPN, and thereby help to determine which failure modes are more sensitive than the others.

Poka-Yoke or “mistake proofing” at the system level helps “prevent” the unintentional errors of commission. It is in my view the best control method because of its preventive approach to defect reduction as opposed to other reactive or responsive approaches, where errors are allowed to occur and then investment is needed for detecting them and eventually correct them, albeit all of that happens post facto. Poka-Yoka has to be the most effective in control method owing to its zero-defect approach with 100% inspection, and fairly low cost deployment, as once the checks/validations are designed in the system itself, there is zero to little need for any warning systems as well any human checking efforts. Statistical Process Control OR Control Charts provides for visibility into the process variation, monitoring if the process is operating as expected, or if at any point a corrective action is required. A process is said to be in stable state when only the common cause variations (those within the control limits) remain, while all the special cause variations (those outside the control limits) have been eliminated. A stable process though may still not be meeting the customer specifications, and so would be deemed as stable yet not capable process, and needs improvements or a redesign. A rather reactive but still a potent tool to detect when to intervene for improvements or plugging the gaps. CBA or Cost Benefit Analysis is the most pre-emptive strike on mitigating the risk of financial loss, as it is designed nip the bad project in the bud. It exposes the projects benefits in quantifiable terms – money needed, time involved and the net gains. It enables the project lead to decide that if the organization strongly desires the project despite CBA not showing favorable results, then what alterations can be made to the design and costs. CBA is mostly beneficial when done it proactively before initiating the project, whereas most of the process improvement initiatives are taken up when the process is already in a state of concern.