One-of-a-Kind Productions in Industry 4.0 Environments

VINCI CARLAVAN, GUIDO; ROSSIT, DANIEL ALEJANDRO

Intelligent and Transformative Production in Pandemic Times

Springer

Año: 2023; p. 573 - 581

Modern production technologies, based on Industry 4.0, allow to increase the flexibility and resilience of production systems. These enhanced capabilities, along with a greater digitization of the shop-floor, give significant leverage to massive personalization of production. This work addresses an extreme personalization problem, where all products are unique: One-of-a-Kind Production (OKP). OKP problems represent those cases where the production process is focused on the customers’ needs and is tailored to their requirements. To address the planning of this type of problems, a CONWIP strategy was used to control production, avoiding overloads in the shop-floor. A particular detail of this work is that the productive configuration adopted is job shop, which is a non-traditional configuration for CONWIP strategy. Furthermore, to better represent the OKP nature of production orders, a great variability was introduced in the number of operations and time required by them. This feature hinders the CONWIP logic, since adding a new job to the shop-floor may not mean adding a workload similar to that of the job that left the shop-floor. To overcome this situation, 2 new dispatching rules that analyze the workload generated by each job before choosing the next job to be dispatched are proposed: SameOp-pure and SameOp-EDD. These rules consider the number of operations of each production order, and prioritize the jobs following a similarity criterion, dispatching as the next job the one most similar to the job that has just left the shop-floor and thus maintaining the workload inside the CONWIP at a fixed level. Computational experiments were carried out based on discrete-event simulation, and the benefits of these new dispatching rules could be verified, obtaining better results than other traditional rules (EDD, FIFO and critical ratio). It was even possible to verify that under more demanding scenarios, the advantages obtained by the SameOp-pure and SameOp-EDD rules were more significant.