The staff board (Projects -> Schedule -> Actions -> Staff Board) lets you keep track of available staff capacity.   This allows you to ensure you aren't over allocating work to staff, or see who has capacity for upcoming projects or production jobs.

The staff board requires that staff have their weekly capacity entered correctly in their user settings Administration -> Users.

To allocate capacity reducing hours for a staff member, allocate them to tasks and assign a specific number of forecast hours expected for the individual to complete their work.

The staff members capacity will be displayed as a percentage over the selected date period.