Comparative analysis for periodical and random servicing systems considering different working circumstances: A textile application

As is in the textile industry, in some industries the selection of the operator servicing system to improve machines’ efficiencies is made intuitively or according to historical experiences generally. However, these preferences are not felicitous in any case. On the other hand, to estimate and analyze the machine efficiency in the case of multimachine assignment is a difficult issue due to machine interference problem. The solutions proposed such as the prepared tables, analytical formulas and queuing theory are generally for a limited number of machines and involve complex and tedious calculations and are generally insufficient for detailed analysis. In this paper, considering some working circumstances, the effect of random and periodical operator servicing systems on the machine efficiency is compared by using simulation methodology. Also, the algorithm of one of the simulation programs used is given. This study indicates that if the average stoppage rates of the machines assigned to the operator is small and the numbers of these machines are large then the random operator servicing system has superiority over the periodical operator servicing system.