The impact of crew mix on productivity and labor cost of a construction work activity

Abstract

In the conduct of construction, situations may arise where a shortage of craftsmen forces crew compositions with a larger than desirable proportion of unskilled workers to do the work that must be done. The net effect on total labor cost and duration of that work activity is critical. The issue is addressed from the viewpoint of group dynamics and conjunctive work tasks which require interaction of group members and the pooling of their resources in order to do what must be done. Three hypotheses are constructed for testing the relationships between crew size and work output, crew composition and work output and crew composition and labor cost. Analysis reveals that crew size and composition affect both work output and labor cost. Increasing crew size tends to increase work output. Increasing the proportion of unskilled workers on the crew tends to decrease both work output and labor cost. It is concluded that the crew mix phenomenon may be either beneficial or detrimental to overall project performance, depending upon circumstances. Implications for the findings include their impact on schedule balancing, cost control and resource allocation. An analysis technique is developed to assist in interpreting the study's findings as well as to provide a tool to evaluate crew performance where this phenomenon occurs.