Turn process volumes and task times into the headcount you actually need, role by role. Add your own roles, processes and activities — nothing here is fixed.
By default an activity's Volume/mo is typed straight into Step 4. If volume varies through the year, switch an activity to Monthly and enter each month, or to Annual and enter the yearly total — either way, the monthly average feeds Step 4 automatically and that field locks to show it.
Group the work into processes, then list each activity with its monthly volume, time per task, and how effort splits across roles. Each row's split should add to 100% — the bar on the right tells you when it doesn't.
Required (at work) accounts for the productivity factor. Required (on payroll) also grosses up for planned leave and absence, so it's the number to budget headcount against.