Distributed system availability in the case of imperfect debugging process

System availability is a major performance measure for distributed systems. A typical type of distributed systems is the so called Homogeneously Distributed Software/Hardware System (HDSHS), for which identical copies of application software run on the same type of computers. When this type of systems is tested, the software faults detected are usually removed and the availability will increase over time. On the other hand, the debugging process may not remove the faults successfully and it may introduce new faults because of incorrect debugging. This paper presents a general Markov model for the availability analysis of the HDSHS for imperfect debugging process. The effect of imperfect debugging and the sensitivity of the imperfect debugging parameter are investigated. System design and testing scheduling are also studied using this model. ©International Journal of Industrial Engineering.