As described in the Workspace datasets section of Chapter 8, Managing Application Workspaces and Content, the Power BI reports, based on Live connections to published Power BI datasets, are currently tied to the app workspace of the dataset. Therefore, in the absence of an Analysis Services database for Live connection reports or a supported DirectQuery data source, each app workspace and its corresponding app will require its own import mode dataset. The ability to utilize a single source Power BI dataset to support reports and dashboards across multiple app workspaces (and thus apps) is expected in 2018.
Despite new features and capabilities that will increase the scalability of Power BI datasets, particularly Power BI Premium capacity, many organizations will choose either SQL Server Analysis Services (SSAS) or Azure Analysis Services (AAS) to support large-scale deployments.
For example, a BI project targeted at a particular business process and team, such as shipping for the supply chain team, may start out as a large Power BI dataset (.pbix). Once the Power BI dataset has proven to be valuable and stable in terms of business definitions and requirements, the dataset could be migrated to an Analysis Services model. The differences between Power BI datasets and Analysis Services models as well as migration considerations are contained in Chapter 13, Scaling Up with Power BI Premium.