Selection of activities to be crashed for mitigating construction delays

Abstract

Mitigating the effects of delays by speeding up (crashing) the remaining activities is a very common practice in construction especially, when such delays are instigated by contractors themselves. When identifying a suitable activity for crashing, managers and planners might consider the cost-effectiveness, safety, quality, resource implication, and impacts on other components in the project schedule. In practice, many managers and planners would often base their decisions on personal judgment and experience. Surveys were carried out in Hong Kong to capture this experiential knowledge of decision-makers on the selection of 'crashing activities' (activities to be crashed). The first survey aimed to identify the factors pertinent to the selection of 'crashing activities', and a list of 23 selection factors were then compiled to drive the second survey which focused on establishing the importance of those selection factors for delays mitigation. The results indicate that 'safety', 'chances of success', 'resources availability', and 'time for implementation' are the most influential factors when selecting construction activities for crashing. Surprisingly, 'cost' was regarded as one of the least important factors by clients and contractors in this study.