Enterprise Gateway : Set up Data Sources

Hi mittalpatel130,

1. While configuring Enterprise Gateway, do we need any Service Account?

Yes. The On-premises data gateway is configured to use NT SERVICE\PBIEgwService for the Windows service logon credential. By default, it has the right of Log on as a service. Reference: Windows Service account

2. I could not find the exact structure to architect Enterprise Gateway configurations. We have scenario of multiple departments using Power BI with various on-premise Data Sources. I am sure we need to make Gateway administrator per department. Will administrator be able to add different Data Sources to Gateway? 

Yes. On-premises gateway allows multiple users to connect to multiple on-premises data sources

3. How to decide whether one VM (Enterprise Gateway) is enough to serve all the departments at the same time? 

You can install a stand-alone gateway or add a gateway to a cluster, which is recommended for high availability.

4. Will Enterprise Gateway installation be on Single VM or all machines/servers where Data lies? 

Gateway should be installed on a single local computer.

Reference: 
What are Power BI gateways?

On-premises data gateway

Best regards,

Yuliana Gu