A system for discovering business processes from noisy activities logs from various activities performed during the execution of the process. Activities are observed from the noisy activity logs that may include text from manually entered activity logs, chat scripts, emails, voice transcripts, desktop captures, and tool logs, wherein the noisy activity logs are received from multiple person/tool actors with each of the actors performing one or more activities related to one/more business tasks. Extracting information from the noisy activity logs to capture activity based information, and then analyzing similar activities and finding possible paths in the similar activities. The results are used to build a process graph based on the similar activities and the possible paths in the similar activities.