The efficiency of uni-directionally patrolled machines with two robot repairmen

This paper shows how to compute the running efficiency of a set of machines which are repaired by two robot operatives. The machines are fixed on a circular drum which rotates at constant speed against the two operatives. This rotation stops whenever a repair is executed and it is assumed that the repair time is constant. Breakdowns of the machines are assumed to occur at random in running time. The actual problem arises in the practical context of textile winding operations and the results are a useful background against which possible modifications of the currently used machinery may be assessed.