Why is the Visualization Template useful in DISCERN?
In DISCERN the Visualization Template, in addition to providing an intuitive high-level representation of the solutions, enables DSOs to:
- Identify interoperability issues in the systems that implement a particular sub-functionality. Thus, available standards and standardization gaps for each solution can be easily represented in the Visualization Template.
- Describe the physical distribution of the components (e.g., software based applications, devices and communication elements) within the system. In the Use Case Template, it is possible to define which actors are involved in a sub-functionality, but it is not possible to represent how these actors are implemented in the physical distribution of the system. The Visualization Template enables users to do this.
- Establish clear relationships between: the business cases and objectives that explain the benefits derived by the company with the sub-functionality, the technical functions that are required to realize such sub-functionality, the information exchanges between the functions, the standard protocols and data models that enable these information exchanges, and the components that implement the technical functions in the system.
- Carry out impact analysis, security compliance, risk elements, compatibility/comparison between DSOs and the future specification of new features by vendors.
DISCERN SGAM Template (MS Visio)
In order to provide guidance for the modelling process, the creation of SGAM models should be supported by a software tool. This contributes to the objectives of DISCERN in several ways:
- A software application provides support for repeating activities, reducing the efforts for the creation of a SGAM model.
- Modelling rules and guidelines can be integrated in the application reducing the extent of manual quality assurance related activities.
- Models created by different parties can be integrated more easily due to the shared syntax and semantics.
- The electronic representation of the SGAM models allows for possible integration into a tool chain with the objective of further processing of the models data.
As the collection of data in a structured way is of high importance in the early stages of the DISCERN project, the model creation should be supported by an application which easily integrates into the software portfolio of the involved parties and builds on known concepts regarding its usability. For that reason, Microsoft Visio was chosen as the basis for the creation of an SGAM template. Due to existing incompatibilities between different versions of Microsoft Visio, two different templates have been developed in DISCERN:
- DISCERN SGAM Template was developed in Microsoft Visio 2013 and is compatible also with Visio 2010.
- DISCERN SGAM Template Pre-2010 was developed in Microsoft Visio 2007 and is compatible also with Visio 2003. This template includes the basic features of DISCERN SGAM Template.
Basic features of the DISCERN SGAM Template
The SGAM Template is a Microsoft Visio-based tool which contains all functions necessary to represent the architectural description of a sub-functionality in the SGAM Layers.
The template includes five stencil sets to provide the symbols required to create valid models on each SGAM layer. They are named according to the SGAM layer they are intended for:
- Business: Symbols to be used to create models on the Business Layer
- Function: Symbols to be used to create models on the Function Layer
- Information: Symbols to be used to create models on the Canonical Data Model View and the Business Context View of the Information Layer
- Communication: Symbols to be used to create models on the Communication Layer
- Component: Symbols to be used to create models on the Component Layer
The stencil sets can be selected on the left hand side of the application window
Figure 1 - Visio template for SGAM visualization
The Visio template for SGAM visualization contains six pages that refer to the SGAM layers and, in case of the Information Layer, the views on these layers:
- Business Layer: Represents concepts related to the business architecture of a sub-functionality. This includes for examples actors, roles, processes and objectives in context of the sub-functionality Use Case.
- Function Layer: Represents functions that are performed by physical devices or information systems including interactions between functions.
- Information Layer - Business Context View: Represents information objects which are exchanged in context of a sub-functionality Use Case.
- Information Layer – Canonical Data Model View: represents the canonical data model standards which are used to provide the information objects in context of a sub-functionality Use Case.
- Communication Layer: Represents protocols and mechanisms for the interoperable exchange of information between components in the context of the underlying Use Case, function or service and related information objects or data models. Communication can be represented in two ways – point to point and areal.
- Component Layer: Represents the physical distribution of all participating components in context of a sub-functionality Use Case. This includes power system equipment (typically located at process and field level), protection and control devices, network infrastructure (wired / wireless communication connections, routers, switches, servers) and any kind of computers. In the template the Component Layer is used as the background for all other layers except the Business Layer.
The layer that shall be used for the creation of a model can be selected in the bottom Section of the application window below the modelling canvas.
In order to map a Use Case into the DISCERN SGAM Visio Template, three different approaches can be used:
- Bottom-up approach
- Top-down approach
- Mixed approach
Known for example from the software engineering domain, the bottom-up approach proposes starting with the specification parts of a solution without exact knowledge of the scope and structure of the overall solution under design. These smaller parts later are integrated to create the final result. The top-down approach represents the contrasting approach putting a strong emphasis on the planning of the solution under design before beginning the work on its individual parts. Lastly, the mixed approach combines the previous approaches.
The DISCERN SGAM Template includes some additional features which shall enhance the user experience while creating SGAM models and also cover export possibilities. For instance, the template enables the background representation of the Component Layer in the Communication, Information and Function Layers. This feature is especially useful in the bottom-up approach and also in the mixed approach, as these involve the enhancement of the Component Layer model with additional information, like the data models and communication models that are used or the functions that are covered by a component. By providing the Component Layer as a background the user is supported by not having to reproduce the same information twice. This prevents redundancy and inconsistencies which may result from changes on one layer.