This study aims to identify and to classify Open book accounting (OBA) dimensions according to inter-organizational cost management (IOCM) in petrochemical companies listed in Tehran Stock Exchange. In this research, there are 18 statistical society financial and accounting experts listed in Tehran Stock Exchange. By studying the theoretical literature and conducted investigations inside and outside of the country and also the experts’ comments, the OBA dimensions were identified and then classified by analytical hierarchy process technique. According to the studies and experts’ ideas, four dimensions including nature of data and accounting data disclosure practices, uses of disclosed accounting data, conditions of OBA, cost implementation ...