Want to support security at the incident level? Use Helpdesk Data Macros to ensure that only the assigned worker is able to modify an incident. This cool solution by Richard Baker works well with minimal cost and support overhead.
The Altiris Helpdesk Solution provides a robust library of data macros to simplify the coding and implementation of business rules. The PREVIOUSITEM macro is a great tool to query the previous value of a field prior to updating the database.