Critical review of previous studies on labor productivity loss due to overtime

摘要

Timely completion has been one of the most important concern due to its impact on both owner and contractor. When schedule is behind, one of most widely used schedule acceleration methods is working longer time: overtime. Overtime practice is one of key management decision because it may have a negative impact on labor productivity. Since overtime is the most widely used and numerous studies concluded that excessive amounts of overtime work could serious negative impact on labor productivity, quantification of the effect of overtime on labor productivity has been discussed in a number of papers. However, it was found that most studies reviewed in this paper have pitfalls. Most of them are out of date, based on a small sample size, and largely developed from questionable or unknown sources. Very little is known about how and from where the data were collected. Where the data source is known, little is known about other pertinent information, such as the characteristics of the project, work environments, quality of management and supervision, type of work, and trades involved. These information should be clearly provided to the users, who considers overtime to speed up the work, to see whether the result of the previous studies can be applied to the work he/she is currently doing. At the same time, for the researcher, this study will be able to guide what characteristics should be considered when he/she want to quantify the effect of overtime on construction labor productivity so that practitioners will not misuse the result of studies.