If you want to make sure that there are never more than a certain number of task deletions at a time in the project schedules, you can configure a delete confirmation threshold. The threshold value ensures that the user will get alerted if the number of deleted tasks exceeds the set value. From that point onwards, they cannot save the deletion without explicit confirmation. They are presented with options to save and proceed, save without deleting, or cancel the changes. Enabling this setting will mitigate the risk of accidental task deletions to a great extent.

On the other hand, if you do not want users to see any confirmation at any time, you can set the threshold to 0.

To enable a delete confirmation message:

1. From the upper-right corner, click on your user name or avatar and select Administration from the options list.
2. Select the Site Settings tab and scroll down to view the Schedule Delete Confirmation setting.
   
3. Enter the desired value in the text field. Ensure that it is a positive integer. By default, this value is set to 0.
4. Click Save.

See also

Managing Tasks and Milestones