Sabbatical as a Fiscal Tool
A sabbatical can have many purposes, including a very pragmatic fiscal one. For each unit of time worked, a faculty member earns X many hours of sabbatical time, similar to the way staff accrue vacation time. Then, once a faculty member reaches a minimum amount of accrued time, the faculty member can take a sabbatical, drawing down that banked sabbatical time. Upon their return, the process restarts.
Why would this be helpful fiscally? When a faculty member is on sabbatical, their pay comes from a specific sabbatical account. Instead of drawing salary from grants, endowment funds, or a departmental budget, that faculty member effectively disappears from payroll for the period of their sabbatical, thus saving funds on the accounts that would normally be used to compensate them. Therefore, even if a faculty member does nothing out of the ordinary for their sabbatical, the process itself will be a financial savings.
To go further, most universities will allow partial sabbaticals, for example taking 1 year at 50% sabbatical pay versus 6 months at 100% pay. When on a partial sabbatical, the faculty member can designate their effort to preserve specific funding sources. An example would be if a faculty member normally received 50% of their funding from grants, 20% from teaching, and 30% from a departmental budget associated with administrative work. A faculty member stating that they intend to use 50% sabbatical time to begin a new research project could keep their 50% grant support of their salary, but be released from teaching and administrative duties and have that portion of their salary come from the sabbatical account.
Also, it is possible to use sabbatical to free up grant funds. Your Research Administrator can set up your grants such that you are charging effort to the grant, but not salary. Obviously in this case you must continue to work on and make progress on the grant. Each University has its own process for this, so reach out before doing anything. Save all documentation as it is often required when submitting progress reports and final statements for grants.