Office management software with customer service functionality required

We are a real estate company specializing in commercial properties and manage properties (industrial, commercial, and office) in five business parks. We currently have approximately 70 commercial tenants as customers. We are looking for suitable software to organize and manage external services and customer service for our tenants, e.g., in the context of renovations, repairs, maintenance, cleaning, and locksmith work, or electrical and drywall work. We do not employ our own tradespeople or caretakers. We use DATEV for our accounting, invoicing, and personnel management.

The software should meet the following requirements:

• Tenant management (commercial tenants only)
• Supplier management
• Write orders to suppliers with automatic order number assignment
• Assign repair orders to tradespeople or mobile caretakers
• Coordination of the aforementioned service providers
• Management of incoming invoices
• Optional time tracking for employees
• Optional interface to DATEV
• Support for mobile devices
• Local installation

Approximately five software workstations are planned. We work with MS Windows systems.