How do institutions recruit retirees several years in advance?

Institutions and institutions sometimes have people who retire a few years in advance and need to leave early. In order to ensure the normal operation of the department and avoid the brain drain caused by it, the way of recruitment in advance may be adopted. Some units may start recruiting before employees officially leave their jobs, and arrange suitable successors for employees who leave early; However, some units may directly issue an announcement to conduct targeted recruitment for employees who retire early. Either way, it is necessary to do a good job of internal communication and evaluation, and work out a suitable recruitment plan and placement plan.