One requires to evaluate the entire filtration system and design PUPSIT into the system (existing or new). There are certain prerequisites which require to be fulfilled to implement PUPSIT and these need to be reviewed and taken care of right from the start to avoid revising the filter system at a later stage. For example, in most cases PUPSIT will add to the complexity of the system due to the fact that filter wetting fluids require to be captured on the filtrate side, the filtrate side needs to be under atmospheric pressure, the filter may need to be dried after the test before use, vent filters on the filtrate side may need to integrity tested before the filtration process starts running etc. The details of the factors which require to be taken into account implementing PUPSIT can also be found in PDA Points to Consider of Pre-Use Post-Sterilization Integrity Testing (PUPSIT).