4D CAD combines a 3D CAD model with the construction schedule to simulate and display the construction sequence of a project with the computer. First developed about 10 years ago, 4D CAD is now increasingly used to communicate construction schedules more effectively to all project stakeholders and to try out alternative designs and construction approaches before actual construction. Martin Fischer is an associate professor in the Construction Engineering and Management Program, Department of Civil Engineering, Stanford University. He teaches graduate and undergraduate courses on project management. His current active research projects include: Model-based constructability analysis, collaborative 4D modeling, managing coordination and dependence among firms within a virtual corporation, concurrent product process and organization engineering. Dr. Fischer received his MS and Ph.D. in civil engineering from Stanford. He was listed among ENRs Top 25 Newsmakers for 1996 and holds membership in a broad spectrum of industry organizations.