Internet service provider seeks information system

We are an Internet service provider and are looking for an information system. We currently use various IT systems such as CRM, ERP, product delivery, time recording, etc. We consolidate all these systems in an SQL database, and I am currently looking for software that allows me to access this data easily and intelligently. We currently import partial data sets into MS Excel and create reports there. However, pivot tables are no longer sufficient for evaluations and are not flexible enough.

We have the following requirements for the solution:

• Simple and intelligent access to data from different systems stored in a database
• Use of different data fields - Creation of new data fields; business logic
• Generate your own queries, query logic
• High performance
• Excel-style interface desirable
• Flexible reporting
• Access rules, rights/role concepts
• Compatible with an SQL database
• Local, on-premises
• Runs in a Windows environment
• Compatibility with MS Excel – .xls or .csv interfaces – an advantage

Up to approx. 50 software workstations are planned.