This paper studies the single machine scheduling problem for minimizing the expected total weighted deviations of completion times from random common due date. Jobs have exponentially distributed processing times and the common due date is a generalized Erlang distribution. The optimal schedules are shown to be ⁄-shaped. Moreover, we give the optimal schedules when the machine is subject to sto...

Many authors have analyzed queueing systems with server breakdowns. Kendall (1953) studied stochastic processes occurring in the theory of queues and their analysis by the method of imbedded Markov chains. Buzacott and Hanifin (1978) classified the machine failures as operation dependent failures and time dependent failures. Shanthikumar (1982) analyzed a M/G/1 queueing system with time and ope...

This paper considers the impact of inflation on the EPQ model for deteriorating items subject to random machine breakdowns and fixed maintenance period. The demand rate is assumed to be a function of inflation and the demand increase due to inflation. The objective is to determine the optimal production uptime that minimizes the present value of expected total costs per unit time consisting of ...

We analyze a one machine scheduling problem subject to breakdowns and preventive maintenance. The primary objective in this work is to minimize the capacity loss due to rework resulting from breakdowns and potential capacity loss due to unnecessary maintenance. We propose a model where the timeline is split into two alternating regions as risk free and risky regions by assuming that the machine...

Finding flexible schedules is important to industry, since in many environments changes such as machine breakdowns or the appearance of new jobs can happen at short notice. In this paper a minimax formulation is used to develop a coevolutionary algorithm for finding worst case flexible schedules. A population of schedules is used to locate the schedule with the best worst case performance, whil...

This work deals with two models of a single machine subject to breakdowns. The first model is binary-state while the second one multi-state model. Breakdowns are followed by repairs. systems under study tracking type. We use nonlinear predictive control determine optimal repair rates that keep variables as close possible their target. Numerical illustrations sensitivity analysis used assess eff...