Qualification of steam sterilizers

how many runs required to take in case of heat penetration study of fixed load at different positions

For qualification purpose,3 runs required whereas for requalification,one run is sufficient.

While performing requalification results from the previous qualification are confirmermed.So one run at requlification ok but if any modification is done in cycle or load pattern in existing cycle go for 3 run to validate the changes made in requlification studies.