Why does the Resource Availability field not reflect the calendar set for the resource?
Resource Availability is a percentage of the calendar hours. It is a rate. If you change the calendar hours the resource's availability will change.
Either the Availability field was edited which edits the resource calendar, or the resource calendar was edited which is reflected in the Availability field.
If you want the resources Availability to reflect the calendars shift then reset the resources calendar to the base calendar.
Example: if you have a standard calendar of 8 hours, and a contractor calendar of 7.75 hours. If the resource is set to the standard then their availability is 8 hours. If you change to the contractor calendar the availability is 7.75 hours.
If you change back to the standard calendar and edited the resources availability to 7.75 hours. Now change back to the contractors calendar a calculation is done based off of the previous change.
8 hours divided by 7.75 gives a .969 difference. When you change back to the contractor calendar the calculation is 7.75 times .969 the difference) which equals 7.51. 7.51 is what is now displayed in the availability field.
To correct this change to the standard calendar. Select your workdays and click on Reset to Base. This will clear edits to the resources calendar. Now when you change between the calendars, the availability will depend on the base calendar shift and not edits to availability which makes changes to the resources calendar.
NOTE: Making changes to the availability or calendars will impact the amount of processing time needed for Time Slicing job to catch up to these changes.
Reference TEC439197 : How to set the default Resource Availability Rate
Reference TEC525604 : How are Allocation, %Allocation, and Availability calculated on the Resource, Projects or Detail pages?
Reference TEC435572 : How should I configure my Time Slices?
Reference TEC1007349 : FTE is incorrect for resource's who's availability does not match the Standard Calendar
Reference TEC1112555 : How is full-time equivalent (FTE) allocation calculated?