Impact of conversion technology on productivity in masonry construction

Developed in this study is a methodology for evaluating productivity losses in masonry construction. Comparable measures of productivity are quantified, and a relationship between productivity and the factors that influence it is established. The strength of this approach lies in its ability to compare productivity levels in developed and developing countries and to quantify the impacts of the various factors contributing to these productivity levels. The methodology was then applied to evaluate masonry productivity at five sites in Jordan, which provided some insight into the broader question of construction practices in developing countries. The productivity at the Jordanian projects was compared with the productivity at sites in the United States and the United Kingdom. This comparison involved determining both the quantitative and qualitative differences between databases by using statistical parameters such as baseline productivity, as well as qualitative assessments of the conversion technologies and exogenous factors that impact productivity. Among the important conclusions from this study are the following. (1) The variation in the baseline value from one database to another database is a function of the conversion technology used, as well as exogenous factors. The baselines for the United States and United Kingdom were essentially the same, while the Jordanian projects had a higher baseline that reflects a lower overall productivity. (2) The baseline for skilled labor manifests little difference among the various databases; however, the baseline for unskilled labor differs significantly between the US/UK and Jordan databases. Conversion technology accounts for a significant portion of this difference. (3) The most significant work environment factors impairing the productivity on the Jordanian projects were material shortages, lack of proper equipment, and rework. (4) Material shortages on a given day impacted not only the performance on that day, but on the preceding days as well. When a material shortage was anticipated, work crews would often decrease productivity for a period of several days in order to sustain a continuous workflow.