In construction projects, losses of productivity often lead to additional costs and time delays. Suboptimal working conditions influence the labor productivity of workers and have an effect on the number of working hours required, for instance, to produce one cubic meter of reinforced concrete. Costs can be reduced and total productivity increased if the sources of potential losses of productivity are identified at the process planning stage or in early project phases. An expert survey conducted in 2014/2015 at Graz University of Technology, Austria, collected data on the losses of productivity that most frequently occurred in conjunction with reinforced concrete works in the shell construction phase. A standardized questionnaire was used for this survey. In addition, an interview was held with each of the experts to discuss the questionnaire in order to improve the quality of the survey and to gather important background information that prompted the responses provided by the experts. For this survey, reinforced concrete works were divided into ramp-up, main construction and final phases. Experts from Austria and Germany were able to select from a range of predefined losses of productivity and to specify other losses separately. This paper reports on the progress of the survey and refers to the related analytical methods. Furthermore, findings of the expert survey are represented in bar diagrams and interpreted. The survey revealed that the main construction phase was generally associated with the greatest potential for losses of productivity. Furthermore, most frequently stated losses of productivity varied depending on the specific construction phase. Future construction projects should particularly focus on the losses of productivity that were most frequently mentioned in the expert survey. The benefit of this approach is that it will provide the opportunity to implement early compensatory measures and to minimize the potential for losses of productivity.
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