1. IntroductionSpecialty contractors – generally known as subcontractors – perform the majority of the work on commercial construction projects. It is common for a typical construction project to use dozens of subcontractors, with 80–90% of the work on most construction projects in the United States performed by subcontractors (Hinze and Tracey 1994). Subcontractor performance is critical to project success (Arditi and Chotibhongs 2005; Gray and Flanagan 1989). Commonly, subcontractors must perform work on multiple projects simultaneously (Sacks 2004), but with limited resources, each subcontractor strives to maximize its workload at any given time for optimal use of resources (Mathews et al. 2003; O 'Brien and Fischer 2000). . Therefore, subcontractors' work activities are subject to individual resource constraints (Kim and Paulson 2003). During construction, changes frequently occur that conflict with subcontractors' capacity constraints, causing an immediate reallocation of resources (O'Brien and Fischer 2000). As a result, resource allocation due to frequent changes presents a critical challenge for subcontractors. Due to frequent changes, subcontractors typically swap resources between projects and strive to understand potential impacts after resource reallocation. Unfortunately, most existing tools are too complicated and provide limited support for reallocating resources between projects, especially for rapid what-if analysis scenarios for decision making. This leads to a reliance on manual resource allocation methods. In response, this paper presents a tool for multi-project resource allocation. A test case with a variety of projects and activity durations is presented to demonstrate the tool.2. Literature Revi...... middle of paper ......lulu, HI., United States, 593-599.Sturts Dossick, C., & Schunk, TK (2007). “Subcontractor Schedule Control Method.” Journal of Construction Engineering and Management, 133(3), 262-265.Tommelein, I. D., Riley, D. R., & Howell, G. A. (1999). “Parade Game: Impact of Workflow Variability on Business Performance.” Journal of Construction Engineering and Management, 125(5), 304-310. Turner, J., & Speiser, A. (1992). “Program Management and Related Information System Requirements.” International Journal of Project Management, 10(4), 196-206.Whittaker, S., and Schwarz, H. (1995). “Back to the Future: Pen-and-paper technology supports coordination of complex groups.” Conference on Human Factors in Computing Systems, 495 – 502. Zhang, H., & Tam, C. M. (2003). “Confused Decision Making for Dynamic Resource Allocation.” Construction management and economics, 21(1), 31-41.