An annoyance working with OAS, as with its predecessor OBIEE, is the fact that one of the core design components, the Oracle BI Administration Tool, is only supported on MS Windows. However, it has already been shown that it actually can be run if you use Wine on Linux. The post on Rittman mead by Borkur Steingrimsson for OBIEE 12c shows that it can work a connect both online and offline.