If you are using MS Excel for your business and you want a relational professional MS Access database then please contact with me. I am a professional MS Access and SQL database developer. I can provide you best solution and provide you an excellent relational database with user friendly UI.
Things I will provide:
1. Multiple user enabled split database with auto-re-linking function to connect with the backend automatically.
2. Professional user friendly UI.
3. Individual login screen with various authorization like admin, user, reporting etc.
4. Long term support whenever you require.
5. Import your existing historical data and provide complete demonstration to understand the workflow.
6. According to your current data I will create all relational tables. If your data size is too high then I can create SQL server backend.
Contact with me and I can assure you that I will meet your expectation easily.