The comparison of two U-shaped lines with an individual variance on some tasks

The Allowable Time Approach of the Uncertain Task for Three U-shaped Lines with the Minimum Workstations

“…The uncertain tasks of three U-shaped Lines determine the time as an interval. They differ from the uncertain tasks of three previous papers which were the scenario time [12,[25][26]. The uncertain tasks of UL-1 which correspond to the [25] paper deviate from the normal time between -1 and 1.…”

“…The uncertain time of first UL and second UL was the optimistic time and the most optimistic time, respectively. The number of workstations of second UL was less than the number of workstations of first UL [12].…”

“…The interval time does not know the probabilistic distribution [11]. The UL implementations for the manufacturing industries are indicated by the conference paper [12]. The benefits of the UL are admirable.…”

“…They are changeable. The instances of the changeable task time are indicated by the conference paper [12]. For the stochastic UL model, Urban and Chiang applied a chance constraint programming for the UL model and utilized a piecewise linear program for the UL solution.…”

“…The uncertain tasks of UL-2 which correspond to the [26] paper deviate from the normal time between -1 and 1. The uncertain tasks of UL-3 which correspond to the [12] paper deviate from the normal time between -2 and 2. Three UL models formulate the cycle time constraints which do not concern the parameters approximation of the uncertain tasks.…”