Kinetic Monte Carlo (KMC) atomistic process simulations mimic the jumps and interactions of individual atoms, based on jump rates derived from ab initio calculations or experiments. By only following ‘defect’ atoms (unlike molecular dynamics), KMC can simulate the typical long annealing times (seconds to hours) used in materials processing. Thus, it provides a detailed and accurate link between parameters obtained from ab initio calculations and experiments performed under typical processing conditions. We describe the simulation scheme and discuss some of the unique features of this simulation technique with the help of results obtained with it.