While setting utilization, you can choose two additional options - use billable capacity, and utilization affects the billable capacity. These two options are connected, as one is dependent on the other.
It is best to explain the mechanism with an example. Jessica is a project manager. We want to allocate time in her calendar for internal activities: 1on1s, management meetings, and team development. We plan the budget for these activities for the entire year. We assign her to an internal, non-billable project, planning her work for 25% of her capacity.
Even though this is a non-billable project, we need this work to efficiently manage other people's work on billable projects. Check the Utilization affects billable capacity checkbox. In this way, we reduce her capacity - the amount of time Jessica can devote to monthly billable projects. These 25% are thus firmly logged into Jessica's calendar. You can recognize projects like this one by the stripes.
Jessica will be working on a client project from March to May. If we log it in 100%, it will always end up in overbooking per month. Therefore, when creating the following assignments, we select the Use billable capacity option to tell the calendar to "take what's left."
If we do not choose this option, there will be overbooking: Jessica will have planned more work than her capacity.
We set 25% capacity and checked utilization affects the billable capacity box. This is how it will look in the employee's calendar.
Now, let’s add another project. This time, we have decided that out of the capacity our employee has left, we will assign 100% of it. For this to work, we also need to check the use billable capacity.
Now let’s see how it looks in the calendar:
As you can see, Primetric assigned 50% of the “leftover” capacity for our second project.
If you set your first project to cover all capacity (100%), Primetric will not allocate any hours during this period, as shown in this screenshot.
With that system, you still can overbook hours. If you, for example, add another project that will use billable capacity and set said the capacity to 100%, you will end up with a situation where your employee is overbooked. The same can happen if you set two projects affecting billable capacity, and their overall % capacity will be over 100%.
Summing up, two checkboxes allow you to manage relations between assignments.
Utilization Affects Billable Capacity
Which decreases billable capacity by the time you schedule for a particular project. It sets the project as overriding.
Use Billable Capacity
Which allows you to schedule the leftover capacity in another billable project and sets it as, we can say, subordinate.