Consulting service provider (occupational safety) seeks order management or complete solution

We are a consulting service provider in the field of occupational safety and are looking for a suitable order management or complete solution to optimize and document our daily tasks.

The software should meet the following requirements:

• Customer and employee management
• Display different billing types for each customer
• Flat rates
• Fixed price
• Hourly rate
• Travel expenses (various billing types, e.g., flat rate, included in the price, or $0.30/km)
• Invoicing
• Cancellation
• Time tracking (also offline) for office employees, mobile for field staff and freelancers
• Vacation and absence tracking, employee scheduling
• Create work records for customers
• Employees should be able to record their working day in it
• Time sheets for the HR department (possibly with travel expenses?)
• Evaluation of employee performance and customer key figures
• Interface to accounting software or financial accounting (possibly also integrated financial accounting)
• Different rights assignment
• Compliant with the principles for the proper management and storage of books, records, and documents in electronic form
• Interface to DATEV and, if necessary, Lexware
• Web-based or on-premises possible

The software workstations will include 10-14 office workstations, 12-16 for field staff, and 6-10 for freelancers (in the field).