I have a question about the difference between Available Capacity and Net Availability

Two resource availabilities

The actual availability of resources or team members to work on projects is often (much) less than their total working hours, for example 5 days at 8 hours = 40 hours per week. 

Often resources are on average 80 % available to work on projects (32 hours), however this percentage can vary a lot as well. Some are 50 % available, some 60 %, etc..

On the other hand, when it is needed that a critical project task is completed as quickly as possible, people can be full-time available and dedicate 40 hours per week to this task (assuming a person has a calendar availability of 5 days). And this is perfectly fine as long as their average workload does not exceed for example the 80 %. 

When calculating the duration of (critical) project tasks and projects, it is therefore realistic to this against the "calendar" availability of a person.  

To deal with this situation, two different availabilities can be defined via the resource table:

• Calendar availability (or maximum availability)
• Nett availability (or average availability)

A big advantage of distinguishing between these availabilities is that projects can be scheduled against the maximum availability and at maximum speed, while at the same time the workload can be monitored and managed against the average availability. 

 In the picture below the two availabilities are defined for Steve Horner:

Measuring average workload against the Net availability

In the Multi-project resource load information both availabilities are displayed. 

In the example below the average workload of 240 hours for System Testing, is offset against 50% netto availability of both Steve and Tom (the blue line). This results in an average workload of 45% against a planning horizon of a quarter.  

If Steve and Tom would have had a 100 % availability, their average workload will be 23 % for the quarter 

Net availability in the Scenario wizard

The  resource load for skills that are not selected for staggering is by default measured against the Nett availability as well. See picture below: