The MUlti-level Simulation Approach (MUSA) is a simulation methodology that employs different tools and abstraction levels to reduce simulation overhead but maintain high precision. MUSA targets HPC applications which use both MPI and OpenMP and allows simulation of high level runtime events. MUSA’s simulation infrastructure is capable of changing the level of simulation detail, from cycle-accurate microarchitectural simulations to high-level analytical models. The methodology enables the combination of detailed (higher computational cost) and high-level (higher simulation speed) simulations, enabling simulation of large-scale machines with thousands of cores in a reasonable amount of computational time, while guaranteeing a high degree of accuracy.