You can use R/3 Travel Management - which is made up of the two components R/3 Travel Planning and R/3 Travel Accounting - to perform all business procedures involved with business trips. To make full use of the functionality of Travel Management, you need to set up not only Customizing for each individual component but also the integration of Travel Planning with Travel Accounting.
If you want to transfer the travel accounting results to payroll accounting, special customizing for integration with payroll accounting is necessary.