Current schedule updating techniques rely mainly on field reports to specify completed work. Information provided in these reports are then manually summarized, analyzed, and input to a computer program to generate an updated schedule. Among other things, recorded items are usually at the very detailed level compared to the more abstract network activities. This makes it difficult to trace each work item recorded to the corresponding network activity or activities making these manual approaches tedious and time consuming. Also, initial logical links are usually not modified, and revisions of durations for future activities are not considered. This paper describes a computer model for automatic updating of project schedules. The model utilizes pen-based computer technologies and computer aided design (CAD) capabilities for site data acquisition. Several modules are defined for modification of network logic, revision of activity duration, and reevaluation of schedule dates. The modules are implemented using a knowledge-based expert system approach.