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Both service rates improved while the total fell
Two service channels can each improve while their combined rate falls. A board needs to understand the changing mix without losing sight of the customers whose promises were missed.
A falling percentage invites a familiar management conversation. Someone asks what deteriorated, another person offers an explanation and a proposed response follows. The direction of the number can become the premise before anyone examines what population produced it. That sequence is understandable when a board receives many measures and limited time. It is also dangerous when a changing composition can move the total in a different direction from every relevant group inside it. The first useful question is not always why the rate fell. It may be which counts were combined to produce it.
