Reliability and availability are two common measures used to evaluate the dependability of computer systems. The authors analyze the reliability and computation-communication availability of multicomputer networks for multiple faults with and without repair. Simulation models are developed that are based on task requirements, graceful degradation and the computation and communication capability of the system. The effect of component failure rate and repair rate on the dependability of multicomputers is also presented. The model accepts the adjacency matrix of a multicomputer graph as the input and hence is suitable for all types of networks. Typical results for 16-node loop, complete-connection, hypercube, mesh, and tree structures are compared.