Synchronization of production and delivery with time windows in fixed-position assembly islands under Graduation Intelligent Manufacturing System

Abstract

The layout of fixed-position assembly islands (FPAI) offers flexibility and efficiency for the production of bulky or fragile products with medium variety and volumes. With the unique production operations and customized delivery requirements in FPAI, the manufacturing practitioners are plagued by long waiting times, frequent setups, and high finished product inventory levels, which are mainly caused by the unsynchronous organization and operations of production and delivery. For achieving synchronization of production and delivery with time windows in FPAI, this paper introduces a concept of production synchronization with three pillars of real-time visibility and information-sharing, coordination of decision-making and synchronized operations. Following the concept, a synchronization-oriented Graduation Manufacturing System (GMS) with distinct functional tickets, including job ticket (JT), setup ticket (ST), operation ticket (OT) and twined logistics ticket (LT) is designed to organize production operations in an integrated and synchronized manner in FPAI. The IIoT-enabled Graduation Intelligent Manufacturing System (GiMS) with real-time visibility and information-sharing is proposed for achieving real-time operational visibility in FPAI. Under GiMS, consider customer requirements and production constraints, a coordinated decision-making model of production and delivery with time windows for FPAI is developed. The observation and analysis of the case company show the effectiveness of the proposed concept and approach, with the highest synchronous degree between production and delivery as well as the best performance in simultaneity (lowest waiting times), punctuality (minimum number of tardy jobs) and cost-efficiency (lowest setup times).