Sassy U makes fashion jeans out of a variety of denim materials that differ in thickness, stiffness, drape and weave. Customers receive a sampling of product in each type of material before final orders are placed. Each day, bolts of denim cloth received from suppliers wait their turn in the cutting department. The cutting sequence is developed from an algorithm called Johnson’s Rule which examines the time required for spreading the cloth on a cutting table (plus marking the pattern) and the time required for cutting it into pattern pieces that will later be sewn together. These times can vary considerably due to number of pattern pieces, pattern placement (matching stripes, for example), cloth thickness, and whether the cutting is to be performed by hand (with an electric knife) or by a CNC textile-cutting machine.
a. Given the time data below, determine the optimal sequence of denim cloth through the cutting room so that makespan is minimized. b. Map out the spreading and cutting processes on a Gantt chart and calculate the makespan. c. Using the sequence determined above, when will the stretch denim material leave the cuttingroom?