When tasks are set as mandatory, this will disable a check-out as well as Pause Day functionality for a rep until ALL the assigned activities are submitted/completed for a particular visit.
At present, tasks can be set to mandatory for the whole account or none of it. It can not be set as mandatory only for specific reps, places, or schedules.
1. Click on the Gear icon and then click on Settings. Click on the Application Settings.
2. Click on the Schedules heading, and then click on the checkbox "Enable mandatory tasks" and Save the change.