Trying to understand how this product is divided, I invested some time on the support documentation provided by Siemens.
The main 2 components of SIMATIC IT are Production Modeler and Components:
1. SIMATIC IT Production Modeler offers a modeling environment in which the various functions provided by SIMATIC IT Components are graphically combined to define the execution logics representing the operating procedures.
These logics are called Production Operations and are presented as rules (workflows), in which each step represents the execution of a function provided by a component.
The main layers you can model with production modeler are:
1.1. Plant Model: physical or logical elements that are used in the manufacturing cycle, and represent the Shop Floor. For instance: packaging line or LIMS.
1.2. Execution Model: Once the plant model is properly defined, it is necessary to describe the plant behavior. Physical and Logical elements must be synchronized and coordinated in order to support the operating procedures representing the plant’s daily operations.