Prior to any licensing or deployment planning, an organization should be very clear on the capabilities of the Power BI Report Server in relation to the Power BI cloud service. The Power BI Report Server does not include many of the features provided by the Power BI cloud service, such as the dashboards described in Chapter 7, Designing Power BI Dashboards and Architectures, or the apps, email subscriptions, Analyze in Excel, and data alert features reviewed in Chapter 11, Creating Power BI Apps and Content Distribution. Although new features are included with new releases of the Power BI Report Server, the Power BI Report Server is not intended or planned to support the features provided in the Power BI cloud service. 

Additionally, for organizations using SSRS, it's important to understand the differences between the Power BI Report Server and SSRS, such as the upgrade and support life cycle. Mapping the capabilities and the longer-term role of the Power BI Report Server in relation to a current and a longer-term BI architecture and cloud strategy is helpful in planning for the Power BI Report Server. 

The following list of five questions can help guide the decision to deploy the Power BI Report Server:

• Do some or all reports currently need to stay on-premises and behind a corporate firewall? 
  • Power BI Report Server is a fully on-premises solution designed to meet this specific scenario
  • Alternatively, organizations can deploy the Power BI Report Server to virtual machines provisioned in Azure
• Is SSRS currently being used? 
  • Power BI Report Server includes SSRS and thus allows a seamless migration from an existing SSRS server
  • Paginated (.RDL) reports are not currently supported in the Power BI service
• Are the primary data sources for reports located on-premises and expected to remain on-premises?
  • As an on-premises solution, the On-premises data gateway is not required to connect to on-premises sources
  • As discussed in the previous chapter, some degree of query latency, hardware, and administrative costs are incurred by using on-premises data sources with the Power BI service
• Are there features exclusive to the Power BI Service that is needed?
  • The Power BI Report Server is limited to rendering Power BI reports (.PBIX) files, as will be discussed in the following section
• Will large import mode Power BI datasets be needed or will the Power BI reports use DirectQuery and Live connections?
  • The size of files that can be uploaded to the Power BI Report Server for Scheduled refresh is limited to 2 GB
  • Additionally, unlike the Power BI service, a single Power BI dataset cannot be used as a source for other reports
  • With Power BI Premium capacity in the Power BI Service, 10 GB and larger files (datasets) are supported

Given these considerations, organizations with significant on-premises investments or requirements should consider the Power BI Report Server as at least part of their BI architecture. One example of this is a large on-premises data warehouse with many existing paginated (.RDL) SSRS reports built against it.

As described in the Hardware and user licensing section later in this chapter, new Power BI reports deployed to the Power BI Report Server can later be migrated to the Power BI cloud service via the same licenses. For example, a group of related Power BI reports initially published to a folder on the Power BI Report Server could later be uploaded to an app workspace in the Power BI service. The app workspace could be assigned Power BI Premium capacity and thus the reports could be distributed to all users, including Power BI Free users, via an app, as per Chapter 11, Creating Power BI Apps and Content Distribution. In addition to a straightforward migration path, many features exclusive to the Power BI service, such as dashboards, can leverage reports originally deployed to the Power BI Report Server.