Among the new non-volatile memories gaining attention as a potential replacement for flash technology is the programmable metallization cell (PMC) that works by creating and dissolving a conductive bridge across a solid electrolyte film. This enables switching between a high resistance state (HRS) and a low resistance state (LRS). The dominant mechanism for resistance switching is field dependent ion transport in the film. In this work, we examine, through numerical simulation, the effects of process variation on the impedance characteristics of the PMC in both HRS and LRS, by changing key parameters of the device. These parameters include the material bandgap, affinity and permittivity of each device layer. Finally, we show which parameters have the greatest effects on the impedance behavior.