The model discussed in this paper represents the interactions between design changes, site work, and fabrication shop work for make-to-order products. Being qualitative in nature, it serves as a basis for discussing how inventory and buffers are created in the Sheet Metal Ductwork Supply Chain due to changes in design and installation sequences. The authors chose to model changes in schedule and design because industry practitioners indicated that these are the main causes for variations that disrupt contractors’ work flow. The authors highlight selected feedback links between activities to discuss the implications of communication, timing of demand, and product standardization vs. customization. A number of insights into the model can be abstracted to other supply chains in construction. Other supply chains in construction (e.g., electrical systems, architectural components, precast concrete) can benefit from the analysis as presented.
HVAC Ductwork, supply chain, buffers, information management