Availability Definition

STK Scheduler uses three different time definitions to determine when a task may be scheduled.

These include:

• Availability windows of each required resource
• Scheduling Times of the task
• STK report times (if applicable)

The availability of a resource is defined as the time window or windows when the resource is available to be tasked. For instance, in a report writing task that requires an author, a computer, a printer, and paper as its resources, the author may only be available during business hours, the paper may have to be delivered and therefore may only be available after Tuesday at 10:00, and the computer and printer may always be available.

The availability of each resource is defined independently of any other resource or task. Let's say we have a satellite ground station pass a task that uses a satellite and a ground station as its resources. We know that the satellite has access to the ground station at certain times in its orbit. But because the access is dependent on the position of both resources, it should not be defined by using either of the resource's availability. Similarly if the satellite has other tasks it must perform that limits the time it can accommodate our ground station pass task, then the limited time is dependent on those other tasks. This also should not be defined by availability. If, however, the ground station is closed on Sundays, then its availability is not dependent on any other task or resource and therefore should be defined using the availability property.

A resource's availability may be defined on the Availability Tab of the Resource Definition Form.

If the availability definition of a resource is changed after the resource is included in the resource constraints of a task, the Create Possibilities button on the Resources Required Tab of the Task Definition form for that task must be clicked to ensure the new availability is incorporated in the timeslot calculation.