Cder guidance validating chromatographic methods
Analogous to process Qb D, the outcome of AQb D is a well understood, fit for purpose, and robust method that consistently delivers the intended performance throughout its lifecycle.The broad knowledge obtained from this process is used to establish a method operable design region (MODR), a multidimensional space based on the method factors and settings that provide suitable method performance.The Analytical Target Profile (ATP) defines method performance requirements, and should incorporate a joint criterion for accuracy and precision in order to define method acceptability in terms of the uncertainty of results generated by the method.
It is also used to establish meaningful method controls of which system suitability is one component.
A high level overview of the AQb D steps is depicted in list analytical method performance characteristics as defi ned in USPand ICH Q2(R1).
The benefits of applying Qb D principles to analytical methods include identifying and minimizing sources of variability that may lead to poor method robustness and ensuring that the method meets its intended performance requirements throughout the product and method lifecycle.
Quality by Design (Qb D) is well established in the pharmaceutical industry for manufacturing processes (ICH Q8  for pharmaceutical development and ICH Q11  for development and manufacture of drug substances).
These are important characteristics to evaluate during method development (and provide an extensive data set for setting method controls) as they lead to an accurate and precise method.