This study aims to identify and to classify Open book accounting (OBA) dimensions according to inter-organizational cost management (IOCM). The study selects six university professors in the field of accounting and by studying the theoretical literature and conducted investigations inside and outside of the country, the OBA dimensions were identified and then they were 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 of OBA were identified as OBA dimensions. The results of our survey indicate that the form of data disclosure as well as coordination and planning among team members played essential role for OBA development. In addition, trust and the cost of the second party were other important factors, which must be considered when OBA is applied in any industry.