In the Quality module, after selecting the project, please follow the steps to see the history of a defect.
1. Select "Cases" on the left panel. (You can also access the defect directly from the left panel by clicking on Defects)
2. Select the Case for which you want to see the defect history log.
3. Select the defect for which you want to know the History.
4. The defect description contains the history details (user account, date, time and company) for each step of the workflow.