1. A method of controlling a process performed by a semiconductor processing tool, comprising: inputting a first principles physical model including a set of computer-encoded differential equations, the first principles physical model describing at least one of a basic physical or chemical attribute of the semiconductor processing tool and including 1) a spatially resolved model of a physical geometry of the semiconductor processing tool and 2) a grid set addressing the semiconductor processing tool or a geometry of the semiconductor processing tool; inputting process data related to an actual process being performed by the semiconductor processing tool; setting boundary conditions for the spatially resolved model of a physical geometry of the semiconductor processing tool based on said process data related to the actual process being performed by the semiconductor processing tool; storing in a fab-level library known simulation results obtained from simulation modules in a device manufacturing fab and distributing the known simulation results to other semiconductor processing tools in the device manufacturing fab; solving the computer-encoded differential equations of the first principles physical model for the spatially resolved model concurrently with the actual process being performed and in a time frame shorter in time than the actual process being performed to produce a first principles simulation by: using code parallelization techniques on multiple simulation modules in the device manufacturing fab, and re-using known simulation solutions as initial conditions for the first principles simulation, wherein re-using known simulation solutions comprises searching in the fab-level library for a closest fitting solution which if used for the initial condition would reduce the number of iterations required by the simulation module; providing from the solution of the computer-encoded differential equations solved concurrently with the actual process being performed a first principles simulation result; and using the first principles simulation result obtained during the performance of the actual process to control the actual process performed by the semiconductor processing tool.