What is 4D CAD

Monitoring of building process activities is the basis for effective control and management of a building project. In its traditional way it is, however, time consuming, inaccurate and expensive. To improve the monitoring process researchers are investigating methods to automate monitoring and support project managers with accurate and timely information about activity progress. The chapter describes some of these methods and then concentrates on a solution, which takes into account all three aspects of project management: coordination, control and communication. Activity progress is monitored directly by using a combination of data collection methods, which are based on the building information model (BIM), especially on the 4D model of the building. The resulting system is described, evaluated and discussed.