Statistical static timing analysis (SSTA) is ideal for random variations but is not suitable for environmental variations like Vdd and temperature. SSTA uses statistical approximation, according to which circuit timing is predicted accurately only for highly probable combinations of variational parameters. SSTA is not able to handle accurately deterministic sources of variation like supply voltage. This paper presents a novel technique for modeling nonseparable deterministic and statistical variations in single timing run. © 2012 ACM.