When you customize your project, you can instruct ALM to preserve a log of values for the system and user fields in your project. For details on enabling history for a field, refer to the Micro Focus Application Lifecycle Management Administrator Guide
When the history data is no longer needed, you can choose to delete this data from your ALM project. For example, if you have successfully run the test sets you created, you may want to clear the test history from your project.
You can choose to clear all history data, or you can select a specific entity or field whose history you want to clear. In addition, you can choose to delete history data up to and including a specific date. ALM clears the data displayed in the History tab of the corresponding modules.
For user interface details, see Clear History Dialog Box.