Trace driven simulation is a well known technique for performance evaluation of single processor computers. However, trace driven simulation introduces distortions when used to simulate multiprocessor architectures. Execution driven simulation is the only technique that gives accurate simulation results for multiprocessor architectures though it is difficult to implement. Thisd paper presents SPAM, a simulation kernel that simplifies the construction of execution driven simulators for shared memory multiprocessors. The kernel provides a tracing tool and a set of primitives which allow the execution, tracing and simulation of shared memory parallel applications on a single processor computer. The performance of the kernel allows the simulation of real sized parallel applications in a reasonnable time.