Designing and building heating, ventilation, and air-conditioning (HVAC) systems requires a set of complex activities and handoffs between multiple architecture-, engineering-, and construction practitioners. This paper highlights one part of the HVAC production network, namely the information and materials flow between fabrication shop workers and field installers. The presented work aims to contribute to lean construction theory by describing current practices and strategies contractors use to cope with interacting sub-cycles and the upstream flexibility needed to accommodate downstream uncertainty. Accordingly, this paper explains what HVAC materials are handled and how. It then builds on qualitative data from several companies to illustrate two different production models used to fabricate and install HVAC components. One scenario describes how materials are “pushed” to the site. A second scenario describes how some materials are “pushed” and others “pulled.” Scenarios vary because each contractor has to meet several project demands at the same time, because they have a specific business market niche and fabrication capabilities, different from competitors’. The exploratory research described here paves the way for research into means to evaluate the effectiveness of different types of planning, the development of production system metrics to evaluate and promote better system-wide performance for fabricators and installers, and the implementation of heuristic- or optimisation tools for researchers to experiment with alternative production control scenarios in order to improve system-wide performance. Ultimately, our aim is to create explicit knowledge on how to increase the efficiency, reliability, and profitability of HVAC production systems.
Supply chain mapping, HVAC contractors, specialty contracting, push-driven scheduling, pull-driven scheduling, kanban, lean construction.