Variety is an ultra-fast standard cell characterizer of process variation aware timing models. It generates library models that can be used with multiple statistical static timing analyzers (SSTA) without requiring re-characterization for each unique format. Variety calculates non-linear sensitivity accounting for systematic and random variation for any set of correlated or uncorrelated process parameters. The resulting library models can be used to model both local (within cell and within die) variations and global die to die variations.