There are two (2) Project Scheduling Modes available in Inspire Planner - Manual and Automatic. The Project Scheduling Mode determines the behavior of the Inspire Planner Scheduling engine when you make an adjustment to your Project Tasks that violate your dependencies (predecessor relationships). By default, the Project Scheduling Mode is set to Manual.
This is the default scheduling mode for Projects in Inspire Planner. When the scheduling mode is Manual, and you reschedule a task before or away from its predecessor, you are presented with a constraint violation that lets you choose how to proceed.
When you create a new project with the scheduling mode set to Manual, and you create tasks, it will default the task duration to 1 day. The first task you create will default to the current date as its start date. This then sets the project start date and all other tasks created in the project will also default to the same start date as the project start date.
When you create dependencies between tasks, the dependency type determines when the successor (dependent) task starts or finishes. Successor tasks always plot as soon as possible following its predecessor.
Take for example the two tasks highlighted in the project below. Prepare Kick-off Deck (B) has a Finish-to-Start relationship with Build high-level project schedule (A), which means that Task B cannot start until Task A has finished. This means that the finish date for Task A drives the start for Task B.
When there is a dependency between two tasks, the successor task (dependent task) always starts or finishes as soon as possible following its predecessor. This means that when you reschedule the predecessor task, the scheduling engine will automatically reschedule the successor as soon as possible.
When in Manual scheduling mode, if we reschedule Prepare Kick-off Deck (B) away from its predecessor Build high-level project schedule (A) so that it breaks the as-soon-as-possible constraint, you are prompted to set a "Start-no-earlier-than" (SNET) constraint. You can choose to proceed or cancel.
If you choose to proceed, Inspire Planner will reschedule the task to the date you selected and will auto-populate a constraint type of "Start no earlier than" and a constraint date that is the same as the task start date. This prevents the scheduling engine from moving the task back to its original timeline based on its predecessor.
If you remove the "Start-no-earlier-than" constraint, the scheduling engine will reschedule the task to start as soon as possible following its predecessor.
If you do not want to set a "start-no-earlier-than" constraint, another way to reschedule a task away from its predecessor is to add lag time.
In the example below, notice that when we added a lag of 10 days to the predecessor, it moved the Start Date of Prepare Kick-off Deck (B) to 10 days from the Finish Date of its predecessor - Build high-level project schedule (A). The Scheduling Engine considers the lag time when calculating and plotting task dates.
In summary, manual mode allows you to choose how to reschedule a task away from its predecessor - you either add a "start-no-earlier-than" constraint or you add lag time.
If you attempt to reschedule a task so that it starts or finishes before its predecessor, the scheduling engine will attempt to populate a "must-start-on" constraint and will display a constraint violation dialogue. You will then need to choose how to proceed.
When the project scheduling mode is Automatic and you create new tasks, the Task Duration, Start Date and Finish Date are blank by default.
You can choose to populate task duration, predecessors and other task details and leave start and finish dates blank. This allows you to create project templates without dates.
When you populate the start date for one of the tasks in the project, this defines the project start date. For all tasks without predecessors and that have task duration populated, they will automatically be set to start on the same date as the project start.
For tasks that have predecessors and where the task duration is populated, they will plot as soon as possible following their predecessor.
Unlike manual mode where you are prompted to set a Start-no-earlier-than constraint when you reschedule a task away from its predecessor, in automatic mode, it automatically populates a Start-no-earlier-than constraint for you.
Using the same example above, when in Automatic project scheduling mode, if we reschedule Prepare Kick-off Deck (B) away from its predecessor Build high-level project schedule (A) so that it breaks the as-soon-as-possible constraint, we do not get prompted and instead, it will reschedule the task and automatically populate a "start-no-earlier-than" constraint. All successor tasks are then automatically recalculated.
If you remove the "start-no-earlier-than" constraint, the scheduling engine will reschedule the task as soon as possible following its predecessor.
Just like manual mode, however, you can also reschedule the task by adding lag time.
If you attempt to reschedule a task so that it starts or finishes before its predecessor, the scheduling engine will auto-populate a "Start-no-earlier-than" constraint but the task will always plot as soon as possible following its predecessor. Automatic mode will enforce the predecessor relationships between tasks.
If you need to adjust a task to start before its predecessor, you will need to set a "Must-start-on" constraint and set the constraint date to the start date you wish to reschedule the task to. This will then display a constraint violation.
As mentioned at the beginning of this article, the default Scheduling Mode for Projects is Manual. However, you can change the default Scheduling Mode to Automatic if preferred. This section will walk you through how to change the default Scheduling Mode for your Projects.