Schedule Mechanics & Data
Float Erosion
Float erosion is a steady decline in an activity's total float across consecutive schedule updates -- a trend that can signal a project heading toward trouble well before any single update looks alarming on its own.
Definition
A single update showing a modest amount of float doesn't look concerning in isolation. The same value seen as the latest point in a multi-update decline -- 22 days, then 14, then 6 -- is a materially different signal, since the trend itself suggests the erosion will continue and eventually cross into negative float if nothing changes. Tracking float as a trend across updates, not just reading its current value, is what makes this pattern visible; a single-snapshot DCMA check can only report whether float is currently negative, not whether it's on its way there.
Example
An activity's float drops from 22 to 14 to 6 days across three consecutive monthly updates -- still technically positive at each point, but the erosion rate itself predicts it will go negative the following month if nothing changes.