The SGAM framework is structured into five ‘interoperability layers’. Each layer is represented by the ‘smart grid plane’ that is composed by ‘domains’ and ‘zones’. he SGAM framework allows the representation of smart grid systems and their relationships in the context of their spatial position within the electrical energy conversion chain, information management hierarchies and in consideration of interoperability aspects.

The five ‘interoperability layers’ describe the smart grid system in terms of interoperability requirements between its constituting elements. These SGAM layers are defined as follows:

Each layer is represented by the ‘smart grid plane’ that is composed by ‘domains’ and ‘zones’. The ‘domains’ reflect the electrical energy conversion chain (i.e. generation, transmission, distribution, distributed energy resources and customer premise) physically relating to the electrical power grid. The ‘zones’ characterise the hierarchy of power system management (i.e. market, enterprise, operation, station, field, process) distinguishing between electrical process and information management viewpoints. Thus, every element on the ‘smart grid plane’ be aligned according to its position within the electrical power grid and its role within power system management. The ‘smart grid plane’ is depicted in Figure 1.

Domains	Description
Generation	Representing generation of electrical energy in bulk quantities, such as by fossil, nuclear and hydro power plants, off-shore wind farms, large scale photovoltaic (PV) power – typically connected to the transmission system
Transmission	Representing the infrastructure and organization which transports electricity over long distances
Distribution	Representing the infrastructure and organization which distributes electricity to customers
DER	Representing distributed electrical resources, directly connected to the public distribution grid, applying small-scale power generation technologies (typically in the range of 3kW to 10,000kW). These distributed electrical resources can be directly controlled by DSO
Customer Premises	Hosting both - end users of electricity, also producers of electricity. The premises include industrial, commercial and home facilities (e.g. chemical plants, airports, harbours, shopping centres, homes). Also generation in form of e.g. photovoltaic generation, electric vehicles storage, batteries, micro turbines, etc., are hosted
Non-electrical Vectors	Represents a system that enables the transfer, in space and time, of a quantity of non-electrical energy. Thus, it may be a system that utilises, heat, natural gas, hydrogen or some other agent.

The ‘zones' cover the hierarchical levels of power system management, distinguishing between electrical process and information management viewpoints.

Zones	Description
Process	Including both - primary equipment of the power system (e.g. generators, transformers, circuit breakers, overhead lines, cables, electrical loads, etc.) – as well as physical energy conversion (electricity, solar, heat, water, wind, etc.).
Field	Including equipment to protect, control and monitor the process of the power system, e.g. protection relays, any kind of intelligent electronic devices which acquire and use process data from the power system
Station	Representing the aggregation level for fields, e.g. for data concentration, substation automation, etc.
Operation	Hosting power system control operation in the respective domain, e.g. distribution management systems (DMS), energy management systems (EMS) in generation and transmission systems, microgrid management systems, virtual power plant management systems (aggregating several DER), electric vehicle (EV) fleet charging management systems.
Enterprise	Includes commercial and organizational processes, services and infrastructures for enterprises (utilities, service providers, energy traders, etc.), e.g. asset management, staff training, customer relation management, billing and procurement.
Market	Reflecting the market operations possible along the energy conversion chain, e.g. energy trading, mass market, retail market, etc.