ABSTRACT
Accurate monitoring of construction activities is a prerequisite to detect delays, which have been recognized as the most common and costly problem encountered in construction projects (Alkass et al. 1995, Josephson & Hammarlund 1999, Levy 2002). The only solution to assure a consistent flow of relevant information seems to be automation of data collection (Kiziltas et al. 2008). Many attempts have already been made using various approaches in order to control construction project performance (Navon 2007, Kiziltas et al. 2008). They are based on indicators, like labor productivity (Stauffer & Grimson 2000, Navon & Goldschmidt 2002), use of equipment (Sacks et al. 2002), materials flow (Cheng & Chen 2002, Ergena et al. 2007), or directly measured activity progress, like some recent methods based on site image recognition (Podbreznik & Rebolj 2005, Kim & Kano 2008). Further attempts have been reported where mobile devices have been used by workers to support faster and more reliable data collection (Garrett & Sunkpho 2000, Ward et al. 2004, Bowden et al. 2005).
