Abstract:
The present investigation deals with a machine
repair problem consisting of cold and warm standby
machines. The machines are subject to breakdown and are
repaired by the permanent repairman operating under
N-policy. There is provision of one additional removable
repairman who is called upon when the work load of failed
machines crosses a certain threshold level and is removed
as soon as the work load again ceases to that level. Both
repairmen recover the failed machines by following the
time sharing concept which means that the repairmen share
their repair job simultaneously among all the failed
machines that have joined the system for repair. Markovian
model has been developed by considering the queue
dependent rates and solved analytically using the recursive
technique. Various performance indices are derived which
are further used to obtain the cost function. By taking
illustration, numerical simulation and sensitivity analysis
have been provided.