One of the simpler ways to begin setting goals for measured improvements is to leverage the statistic known as standard deviation. The first standard deviation (or sigma) from the mean is something which has been achieved (or exceeded) by the team at least a third of the time. This makes the target empirically based, measurable, and demonstrably achievable even before it is set. The goal is to move the mean to that first sigma (above or below, depending on whether we are trying to increase or decrease the number/frequency of events). And yes, it involves some F-stat work later to know whether that occurred, but this method also allows us to also watch the variance as it contracts to the best achievable (for current practice).
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