This guideline describes science and risk-based approaches for developing and maintaining analytical procedures suitable for the assessment of the quality of drug substances and drug products. The systematic approach suggested in ICH Q8 Pharmaceutical Development together with principles of ICH Q9 Quality Risk Management can also be applied to the development and lifecycle management of analytical procedures. When developing an analytical procedure, a minimal (also known as traditional) approach or elements of an enhanced approach can be applied. Furthermore, the guideline describes considerations for the development of multivariate analytical procedures and for real time release testing (RTRT). This guideline is intended to complement ICH Q2 Validation of Analytical Procedures.