To appropriately establish system suitability, we need to consider both the parameter that
will be assessed and the numerical or logical value(s), generally articulated as acceptance
criteria, associated with each parameter. System suitability parameters are the operating
parameters that are the critical identifiers of an analytical method’s performance. System
suitability should be demonstrated throughout an assay by the analysis of appropriate
controls at appropriate intervals. It is a good practice to establish the system suitability
parameters during method development, and to demonstrate during qualification that these
parameters adequately evaluate the operational readiness of the system with regard to such
factors as resolution, reproducibility, calibration and overall assay performance. Prior to
validation, the system suitability parameters and acceptance criteria should be reviewed in
order to verify that the previously selected parameters are still meaningful, and to establish
limits of those parameters, such that meaningful system suitability for validation is firmly
established.