The concept of a maximal network plan to enhance automated decision making in production steering

Abstract

Digitalization is a major driver of competitiveness in industry. Especially, automated scheduling systems are broadly available to deal with production steering in complex production systems. Their underlying concept is the network plan to describe the logical relation between diferent production steps for the completion of a production process. The network plan, however, is limited to contain only one standard process and allows therefore basically only the automated variation of execution time of each step within the given logical sequence. This is sufcient as long as the production process and the boundary conditions, such as resource availability, are stable to a certain degree. This work introduces an enhancement of the concept of the network plan, the Maximal Network Plan, that is designed to automatically cope with disruptions. It stores additional alternative sequences, weighted according to their priority in comparison to the standard process. Therefore, a numerical decision making is possible in terms of also varying the order of production tasks to achieve a maximum performance for the overall process. Instead of waiting for a disruption in the standard process to be solved, an alternative sequence will be proposed to increase overall progress by circumventing the blocked step. This concept has been developed and tested for complex assembly tasks, such as the production of air- and spacecraft structures and systems. In conjunction with the use of mobile computing devices instead of paper-based work order documents it allows a very fast and dynamic production steering, also in the case of substantial disruptions in the standard process.