Title: MMAPs to model a warm standby multi-state system with loss of units and a general variate number of repairpersons
Authors: Mohammed Dawabsha - University of Granada (Spain)
Juan Eloy Ruiz-Castro - University of Granada (Spain) [presenting]
Abstract: A complex warm standby multi-state system subject to different types of failures, repairable and non-repairable, is modeled through a Discrete Markovian Arrival Process with marked arrivals (D-MMAP). The system is composed of a general number of units, K, and RK repairpersons. Each unit can undergo a failure at any time. The online unit failure can be internal (repairable or non-repairable) due to wear or external due to one external shock. When one external shock occurs, it can provoke a modification in the internal behavior of the online unit or a fatal failure. Each warm standby system can undergo a repairable failure. A non-repairable failure implies that the unit is removed and in this case the system continues working with a less unit while it is possible. If it occurs, the number of repairpersons is also modified. Some interesting measures, such as the mean operational time and the mean number of events up to a given time have been worked out. Costs and rewards are included in the model and the expected cost up to a certain time is calculated. The number of repairpersons has been optimized according to the number of units in the system. The model is built in an algorithmic form which eases the computational implementation.