You have defined planning plants for your organization.

 According to the SAP S/4HANA Cloud, public edition Learning Journey1, some of the purposes of using a planning plant are: it is used to assign multiple maintenance plants; it is used to plan the maintenance tasks for technical objects. A planning plant is an organizational unit thatrepresents a central planning unit for maintenance work. A planning plant can be responsible for one or more maintenance plants, which are organizational units that represent physical locations where maintenance work is performed. A planning plant can also plan the maintenance tasks for technical objects, which are objects that represent physical assets or pieces of equipment that are maintained in an organization.