Generally speaking, the day an employee informs a manager that she or he is leaving tends to generate “an Excedrin headache.” At bare minimum, some scrambling will take place to find an existing employee who can backfill the position until a suitable replacement can be selected (assuming no hiring freeze).
Often, a decent amount of what the soccer world would call “emergency defending” may be needed—e.g., time-sensitive intervention of cross-training and documentation. When the role is critical and the organization must act quickly to fill the vacuum with a short-term consultant, that can trigger an unbudgeted cost for the department.
