Sequence Planning for Integrated Product, Process and Automation Design

Artikel i vetenskaplig tidskrift, 2010

In order to obtain a unified information flow from early product design to final production, an integrated framework for product, process and automation design is presented. The framework is based on sequences of operations and includes a formal relation between product properties and process operations. This relation includes liaisons (interfaces) and precedence relations, where the precedence relations generate preconditions for the related process operations. From this information a set of sequences of operations (SOPs) is generated. A formal graphical language for hierarchical operations and SOPs is then introduced and defined based on automata extended with variables. Since the operations are self-contained they can be grouped and viewed from different angles, e. g., from a product or a resource perspective. These multiple views increase the interoperability between different engineering disciplines. A case study is performed on a car manufacturing cell, where the suggested modeling framework is shown to give comprehensible SOPs. Note to Practitioners-When designing an automation system, an important challenge is to specify in what sequence the different tasks, or operations, should be executed. This has become a problematic bottleneck in the automotive industry, especially for body-in-white manufacturing. The rising needs on manufacturing flexibility increases the complexity of the entire manufacturing system, as well as its control function, the sequence of operations. This paper proposes a new sequence planning approach, where sequences are viewed based on the relations among operations instead of manually constructing the sequence. By the use of different views the sequence of operations related to, e. g., the part flow, robot operations or operator tasks can be visualized. Different views help the user to easier understand the relation between different parts and components, as well as the total system behavior.