If two or more Activities are ready to start work (Work Items are available to be worked on) but they cannot start because a floating (shared) Resource such as labor is unavailable, then they have to compete to get this Resource.
When a unit of Resource becomes available the Activity that gets it is determined by the Activity's priority.
By default, all Activities have the same priority (50). The higher the priority value, the more important the Activity is in getting Resources. Priority values can be any number between 0 (lowest) and 100 (highest).
The Priority of a Activity can be adjusted dynamically in two ways:
1) Set the Activity's priority method to “Label” and choose and Label name to use. The value of this label for all Work Items at the heads of Queues feeding the Activity will be checked. The highest of these values will be used for prioritizing the Activity's request for Resources. These Label values should be in the range 0-100. If a Work Item does not have the appropriate Label, its value will be treated as zero.
2) If the Activity's priority method is set to “Fixed” then this “fixed” value can be changed from Visual Basic using the SETPRIORITY procedure.