Value-based product structure evaluation for disassembly

Designing for the ease of end of life (EOL) disassembly is an important design function. The product structure that is the spatial relationships between the parts of the product and the value distribution over them plays an important role in determining the ease and profitability of disassembly. This paper presents a conceptual methodology to determine the effect of the spatial precedence on the desired value precedence of the product. The methodology introduces a digraph called the bureau graph to model this relationship between the spatial and value precedence structures. Based on this modeling indices are derived that provide a holistic evaluation of the product structure and also help determine the bottle necks and weak points of the product structure to aid the designer. This approach is explained for the family of unidirectional, fixed precedence assemblies.