Bottom out
Bottom out turns up in 2 fields: statistics, automotive. Here is what it means to the people in each one.
Bottom out in statistics
A process variable or metric reaches its absolute lowest physical or theoretical limit.
A measured value hits a floor where it can no longer decrease. This typically occurs when a measurement reaches zero, drops below the detection limit of a sensor, or encounters a physical hard stop. On a control chart, a metric that bottoms out will show an artificial flatline, which distorts standard deviation calculations and violates normal distribution assumptions.
"The defect rate bottomed out at zero on Tuesday, so the lower control limit on the p chart is completely meaningless right now."
Bottom out in automotive
To fully compress a vehicle's suspension until it hits its mechanical limits.
To compress a suspension system to its absolute maximum travel, causing the chassis or suspension arms to strike the bump stops or the ground. This typically occurs when hitting a deep pothole or carrying excessive weight, and frequent occurrences can damage shock absorbers, oil pans, and exhaust systems.
"The customer complained that the rear suspension bottoms out every time they drive over a speed bump with passengers in the back."