مشخصات پژوهش

عنوان	Online Companion for “Minimizing Cycle Time in a Blocking Flowshop”
نوع پژوهش	مقاله چاپ‌شده در مجلات علمی
کلیدواژه‌ها	manufacturing, blocking flowshop, slowing down, traveling salesman problem.
چکیده	We consider a flowshop which repetitively processes a minimal part set. The absence of intermediate buffers between machines causes the blocking of jobs when downstream machines are occupied. The objective is to minimize the cycle time, or equivalently to maximize the throughput rate. This problem is formally intractable. Optimization software becomes impractical for instances larger than approximately five machines and eight jobs. The best previous heuristic procedure solves instances with nine machines and 25 jobs with relative errors averaging about 3%, but sometimes as much as 10%. The idea of deliberately slowing down the processing of operations (i.e., increasing their processing times) establishes a precise mathematical connection between this problem and a no-wait flowshop. This enables a very effective heuristic for the no-wait flowshop to be adapted as a heuristic for the blocking flowshop. We also describe Lagrangean relaxation and decomposition methods to generate lower bounds on cycle time. Our computational results show relative errors that average less than 2% for instances with 20 machines and 250 jobs. We also indicate how various well known practical problems can be modeled as blocking flowshops.
پژوهشگران	Chelliah Sriskandarajah (نفر سوم)، نیکلاس هال (نفر دوم)، عیسی نخعی کمال آبادی (نفر اول)