A novel product representation to highlight cross-assembly dependencies and product robustness

Manufacturing industry has traditionally used Bill of Materials (BOMs) and Product Lifecycle Management (PLM) tools to track components and sub-assemblies within a product. These apply a hierarchical structure to product assemblies and sub-assemblies. Impacts of change to one or more components can easily be traced throughout the assembly tree; however, changes impacting another component not directly or explicitly connected to the first are not considered. Here the authors present the novel Kendrick Reticulated Ontology Model (KROM), a mesh component network to highlight cross-assembly dependencies. N^th-order connections are considered through user inputted links between otherwise unconnected components. Unexpected emergent behaviours can therefore be anticipated. Network analysis was applied to the resulting graph, quantifying the design's robustness though centrality measures. Considering both product components and assembly associated tooling and jigging demonstrates the true propagating impact of design change. It is shown that core component connectedness order is changed when tooling becomes part of the network. This is particularly significant when considering the regular omission of tooling in BOMs. Here, a disconnection between Design Engineering and Production Engineering after design finalisation has been determined and a solution presented.