OOS/OOT statistics
Investigate out-of-spec and out-of-trend results with context.
Summary
This calculator references FDA OOS guidance and USP <1024> guidance for out-of-specification and out-of-trend investigations.
Use historical data to estimate the mean and standard deviation, then compare a new result to the distribution. This provides statistical context but does not replace formal OOS/OOT procedures.
Document investigations and apply laboratory and quality system procedures when results fall outside specifications or established trends.
Step-by-step: Investigate OOS/OOT signals
- Compile historical results
Use representative historical values to estimate the mean and standard deviation.
- Define alert thresholds
Configure warning and action limits based on sigma multiples.
- Evaluate the new result
Compare the new result against specifications and trend limits.
Historical data
Specification and trend limits
OOS/OOT context
Provide historical values to calculate mean and sigma.
Regulatory references
Read-only guidance aligned with major regulatory bodies.