MSP Legacy Driver: In the legacy driver, manually scheduled tasks is not supported.
1. Tasks must be created originally in auto scheduled mode in MSP. This is a required setting when working with the MSP Interface for PPM. f you create new tasks in MSP as manually scheduled, they will not be saved to PPM unless the task has been calculated. Since the Start and Finish dates aren’t automatically defined and these are required fields in PPM, the new task will not save.
MSP New Driver: It's required that tasks created in MSP are created in auto scheduled mode, but it's also recommended to use Auto Scheduled for tasks going forward. Below are some of the things to be aware of if you do set tasks to manually scheduled mode:
To set this required setting for new tasks going forward in a project:
- In MSP, go to File->Options
- Click on Schedule
- Change New tasks created to 'Auto Scheduled'
- Click OK
2. Even if you use have tasks set to manually scheduled, MSP will still auto schedule these (especially after posting) at times by design
3. As mentioned in the following Microsoft KB: When manual scheduling tasks, changes to task dependencies, constraints, and other task data will not automatically update task dates. (For more other differences in using auto scheduled versus manually scheduled see: https://support.office.com/en-us/article/How-scheduling-works-in-Project-5d4f5981-4e9f-4e8e-a699-2ef2a419252f?ui=en-US&rs=en-US&ad=US)
4. If summary tasks are set to manually scheduled mode, the task data below them won’t roll up into the summary tasks (Such as Start/Finish dates).
5. You may see a mismatch in dates and duration. (Example a task is 10 duration, but Task Start/Finish dates incorrectly show as 10/11/2016 and 10/11/2016 respectively.)