Visual representation of construction progress monitoring metrics on time-lapse photographs

A low cost progress data collection technique for construction projects using time-lapse photography or real-time videotaping can provide a wealth of spatial and temporal information for progress data collection. The benefits of using photographs would be maximized if the progress deviations between planned and actual (as-built) performance are visually shown on these photographs. The importance of such visual representation of construction progress is well understood when the participation of diverse parties with different levels of expertise (from owners to subcontractors) is considered. Current formats of monitoring reports (e.g. textual progress reports, progress graphs or charts) may not properly and quickly communicate progress situations and would make understanding of the progress situation difficult. Current methods of monitoring require manual data collection and extensive data extraction from construction documents making progress monitoring a time-consuming process and distracts managers from the important task of decision making. As an effort to address this issue, a visual representation of construction progress is proposed that aims to picture the progress situation on time-lapse photographs (representing actual progress), superimpose the planned progress (obtained from the 4D as-planned model), and provide the clear comparison in an augmented reality environment between as-planned and as-built progress. A series of visualization techniques (e.g. colour and colour gradient) is developed to communicate and visualize detected discrepancies and progress performance metrics. Schedule deviations, construction sequence, budget distribution and earned value analysis metrics (cost performance and schedule performance indices) are also visualized. These techniques if automated could accurately and quickly communicate the progress situation on photographs and provide a powerful tool for prompt progress control decision making.