Laser diode arrays are a high thermal flux electro-optic application where performance and reliability are a strong function of operating temperature. An understanding of the movement of heat in arrays and the effect of material choices on thermal performance are critical to optimum design of arrays. A modeling tool and accompanying methodology are outlined. Simulated diode array performance under a wide array of conditions and can be used to simulate tests that are difficult or cost-prohibitive. Through the development process, models of full 10-bar arrays were found to be accurate in modeling steady state or quasi-steady state performance but insufficient for microsecond transient responses. Initial efforts to incorporate small-scale laser diode properties into a large scale device model are described.