A maintenance plant is the organizational unit in which the technical objects to be maintained are physically present. A maintenance plant can be directly assigned to the following objects:
A maintenance work center, which is a location where maintenance tasks are performed. A maintenance work center can be a person, a group of persons, or a technical object, such as a machine or a vehicle. A maintenance work center is defined by its capacity, availability, and cost rates1
A storage location, which is a place where spare parts and materials are stored within a plant. A storage location can be a warehouse, a bin, or a shelf. A storage location is defined by its address, stock type, and valuation area2
The other options are incorrect because:
A maintenance planner group, which is a group of planners who are responsible for planning maintenance activities in a maintenance planning plant. A maintenance planner group is not directly assigned to a maintenance plant, but to a maintenance planning plant. A maintenance planning plant is the organizational unit in which maintenance requirements are planned3
An organizational unit, which is a generic term for any unit of an organization that performs a specific function or task. An organizational unit can be a company code, a plant, a sales organization, a purchasing organization, etc. An organizational unit is not directly assigned to a maintenance plant, but to a higher-level organizational unit, such as a company code or a controlling area.
References: 1: Maintenance Work Center | SAP Help Portal 2: Storage Location | SAP Help Portal 3: Maintenance Planner Group | SAP Help Portal : Organizational Unit | SAP Help Portal
