Analyzing Schedule Dependency and Sequencing Changes for Robotic Construction Using Graph Analysis

A construction schedule consists of activities and their sequencing. The impact of using robots in construction projects goes beyond a single activity, and affects an entire sequence of activities because of the difference between humans and robots in physical characteristics, work constraints, and work performance. The interdependency among construction activities complicates schedule change analysis through change propagation. This study developed a method for analyzing the impacts of using robots as alternative methods in construction projects. The study aimed to understand the impacts of employing robots in construction scheduling and analyzing schedule change propagation. We first summarize the typical construction sequence dependencies and their causes based on extant literature. Then, we analyze the impact of emerging or currently used site construction robots on these dependencies based on robots' characteristics and work methods, as well as the potential propagation of changes through the activity dependency network using graph theory. A case study project is analyzed to compare the proposed use of robotic construction against the actual methods used in the project, and to understand the changes with and without robotics to analyze the sequence differences. The output of this research is a defined graph-based process for tracking changes in a network dependency schedule, and a clear definition of four types of schedule changes incurred by use of construction robotics in construction sequences.