First Time Right (FTR) Calculator

How this is calculated

First time right at one step is simply the share of units that pass with no rework, repair, or repeat inspection. Across a line, the step FTRs multiply, the same chaining logic as rolled throughput yield (RTY).

Steps left blank, or with zero units processed, are skipped. If units right exceeds units processed for a step, the ratio is capped at 100%.

Why the rolled number matters

• FTR chains multiplicatively. Four steps at a respectable 97% each roll up to about 88.5% overall. Good-looking step metrics can hide a line where one unit in nine needs a second touch.
• The hidden factory. Units that fail first time do not vanish, they get reworked, re-inspected, and re-routed. That rework consumes capacity, labor, and floor space that never show up on the schedule, which is why lean practitioners call it the hidden factory.
• Count honestly. A unit that passes only after adjustment, touch-up, or a second inspection is not right first time. Loose definitions inflate FTR and hide the rework load.
• This is a snapshot, not a control chart. One sample tells you where you are today. Trend it over time before drawing conclusions about process stability.

Rework is one of the classic wastes; the lean manufacturing guide covers where it fits among the others. To connect quality losses to equipment performance, see the OEE calculator, or size the cost of the defects that get past every step with the quality escape cost calculator.