Spice modeling has become commonplace today, especially with the advent of affordable PCs with computing power that surpasses the mainframes of yesteryear.
A major concern in Spice modeling is the accuracy of the models. Without a good model, simulation results are not much more than verification of rudimentary circuit operation. The Boyle op amp model, introduced during the mid 70s, did not need a lot of computing resources and provided reasonable results for the µA741. Since its introduction the Boyle model has been enhanced to add more accuracy.
Today, full transistor models simulate with speed and accuracy on modest home systems. The goal, when creating the SPICE model of the THS4001 high-speed monolithic operational amplifier, is to provide a model that will accurately simulate the actual device in a circuit. The model is derived from the full transistor model used internally by TI design. Simplifications are made to speed simulation time and various performance parameters are adjusted to match the model to measured device performance.