Sequencing and planning of packaging lines with reliability and digital twin concept considerations - a case study of a sugar production plant

Background: The study focuses on simplified make-and-pack production in the sugar industry as a case study. The analyzed system is characterized by parallel packing lines, which share one resource with a sequence-independent setup time. Additionally, the special characteristics that occur in many enterprises make scheduling difficult. The special characteristics of the system are the simultaneous occurrence of a variable input stream, scheduling of processes, and including the reliability of machines. Due to the variability of the input parameters, it is appropriate to consider the use of Digital Twin, which is a virtual representation of the real processes' performance. Therefore, this purpose of the paper is two-fold. First, an analysis of sequence determination of the stream-splitting machine was performed with taking into account the impact of logistics system reliability on system performance. Second, the concept of implementing Digital Twin in the analyzed production process is presented. Methods: The mathematical model for line efficiency was developed on the presented make-and-pack production presented in the selected sugar industry. Different sequences of stream-splitting machines were studied to examine the system's efficiency, availability, and utilization of packaging lines. Two scenarios were investigated with the use of computer simulation. Results: Computer simulation experiments were performed to investigate the sequencing and planning of packaging line problems. The results obtained for the case company indicated a significant dependence between the preferred packing sequence and the operational parameters. Conclusions: The simulations confirm the influence of internal and external factors on sugar line packaging processes. The main advantage of the developed simulation model is identifying the relationship between the size of the input stream and the system's availability level, as well as identifying the main constraints on the possibility of implementing the DT concept in the analyzed company.