A method includes: identifying a timing path of a logic circuit; determining a Boolean expression at an internal node in the timing path; providing a DC vector having a plurality of forms; determining a Boolean value at the internal node for each of the forms based on the Boolean expression; determining a quantity of stressed transistors in the timing path for each of the forms separately based on the respective Boolean value; and determining a best-case form, associated with an aging effect of the logic circuit, and a worst-case form, associated with the aging effect, out of the forms based on the quantities of stressed transistors.