Title: A batch scheduling and operator assignment model with time-changing effects to minimise total actual flow time

Authors: Dwi Kurniawan; Andi Cakravastia; Suprayogi Suprayogi; Abdul Hakim Halim

Addresses: Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, Indonesia ' Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, Indonesia ' Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, Indonesia ' Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, Indonesia

Abstract: This paper investigates integrated problems of batch scheduling and operator assignment with time-changing effects due to the operators experiencing different degrees of learning and forgetting, and accumulating different degrees of fatigue. Each batch will be processed through a number of operations in a flow shop, where each operation can be performed by one of the alternative operators. Each operator will be assigned to a maximum of one machine, and a minimum of one operator will be assigned to each machine. The production process could produce a number of defective products that can be reworked. The problems are formulated in a model, and the decision variables are operators' assignment to machines, the number of batches, batch sizes, items allocation to batches, and the schedule of the resulting batches. A proposed algorithm is developed to solve the model, and numerical examples show that the model and the algorithm work effectively for the investigated problem. [Submitted 30 January 2020; Accepted 15 January 2021]

Keywords: batch scheduling; operator assignment; learning-forgetting; fatigue-recovery; actual flow time.

DOI: 10.1504/IJMR.2022.127091

International Journal of Manufacturing Research, 2022 Vol.17 No.4, pp.422 - 451

Received: 30 Jan 2020
Accepted: 15 Jan 2021

Published online: 22 Nov 2022 *

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