When working with resource costs, you can specify different cost rates for different assignments and apply different cost rates at different times.
You can account for variable resource availability over time (via a resource’s Max. Units value), which allows you to more finely control when a resource will appear to be overallocated.
In a usage view you can edit the scheduled work values of resource assignments over time. For example, you can delay the start of one resource on an assignment without affecting the other resources assigned to the same task.
Material resources, when assigned to a task, can have a fixed or variable consumption rate.