ACTION-RESPONSE MODEL AND LOSS OF PRODUCTIVITY IN CONSTRUCTION

Unanticipated conditions on a construction project sometimes result in a significant loss of productivity. The conditions that may affect pr oductivity-adverse weather, scheduled overtime, and material shortages , to name a few examples-have received considerable attention in the l iterature. However, both experience and a detailed examination of this literature reveal that these conditions do not necessarily lead to a loss of productivity. Furthermore, when such losses are observed, thei r extent varies from project to project, from activity to activity, an d from crew to crew. Other factors and processes must therefore be inv olved. The action-response model of productivity loss in construction identifies these factors and processes. The model graphically depicts how a variety of factors may interact to cause a loss of productivity: how a crew is influenced by these factors and how the management of c rews can mitigate, eliminate, initiate, or exacerbate any particular l oss of productivity. By applying the model to three case studies, a ne w approach to evaluating loss of productivity is illustrated.