So Many Flows!

Flow is one of three perspectives in the Transformation-Flow-Value (TFV) conceptualization of project production systems. Accordingly, many papers published in the IGLC proceedings and elsewhere have addressed flow on a theoretical or practical basis. This notwithstanding, quite a few of these papers describe various flows only loosely without defining them formally. For example, a term such as workflow is widely used in the Lean Construction literature, but what exactly does it refer to? This paper poses the question: What kinds of flow can be distinguished? In response, different kinds of flow are listed, some already well-described and others (e.g., assembly flow) seemingly overlooked in the Lean Construction literature. The contribution of this paper is distinguishing and defining a certain number of flows in construction, using a vocabulary that is internally consistent. Flows need comprehensive attention in the design and execution of Lean Construction systems, so it is important to be clear on terminology. The goal of providing definitions regarding flows in Lean Construction is to facilitate research and communication of ideas with scholars and practitioners around the world.