Skip to content

Role of Common Information Model (CIM)

What CIM is and Why ?

The Common Information Model (CIM) is an open standard for representing power system components originally developed by the Electric Power Research Institute (EPRI)

CIM

  • is an information model for the utility industry

  • is an abstract representation of real world objects

  • gives unique names, definitions and meaning to each object and attributes to avoid confusions

  • describes relationships between objects

  • is not tied to a particular application

  • defines generic interfaces and messages

  • enables integration of applications and systems

  • is extended with market information

  • is described in UML and maintained by IEC in Sparx EA

  • is not new "thingie"

What CIM is not ?

CIM

  • does not specify or define a physical data model or physical data store. It is a logical information model that is intended to be used in message definitions between separate systems.

  • based systems or applications don’t need to store their data natively in CIM format for them to be able to externally connect to other systems via CIM.

  • does not dictate platform technologies such as Windows, Linux, Java, C++, C#, Oracle, or SQL Server. In fact it is intentionally considered to be technology agnostic.

  • information models extending is acceptable and even anticipated.

There is nothing preventing it from being adapted to be used as a definition for a physical database, but that is not its originally intended purpose; nor is there a strict definition of what a CIM-based physical database should look like

In other words, a software system that is CIM-based doesn’t have to have a database schema that uses the CIM rather it should have interfaces that have messages defined based upon the CIM.

Most cases it is probably better for the applications to have a database structure defined in a way that optimizes the use of the data for that application.

CIM Overview

  • Each package and class is represented in the CIM Standard document using:

    • Diagrams

    • Text containing the attributes with a description and a list of its parameter

  • Each Package contains a set of object/classes

  • Each object/class is defined in terms of:

    • Attributes

    • Relationships (associations both within and between other packages)

A Power System Resource (PSR) is a fundamental class in utility information models, representing physical assets within electrical transmission and distribution networks. Examples of PSRs include Generating Units, AC Line Segments, and Transformers. Each PSR is characterized by specific attributes that define its operational and technical properties.

For instance:

  • An AC Line Segment has attributes such as serial numbers, spatial coordinates, length, and rated voltage.

  • A Capacitor Bank includes attributes like impedance, maximum/minimum kV rating, and control settings.

By standardizing these classes and attributes, utilities ensure consistent data representation across systems—enabling better asset management, grid monitoring, and interoperability between applications like SCADA, EMS, and GIS.