Business Process Model Semantics

Outlined below are the key conventions and the semantics of the diagrams used in this Business Process Model.

The diagram hierarchy

The model shows the sequence and timings of business processes covered by the Balancing and Settlement Code (BSC) as a hierarchy of Business Dynamics diagrams.

The hierarchy of Business Dynamics diagrams represents increasing detail about processes shown on the diagrams. A high level process is detailed in a lower level diagram showing the flow of events through sub-processes covered by that high-level process.

If a process is further decomposed the process box is marked with a dot at centre bottom.

Titles of diagrams include their level number, from 0 for the highest level diagram to 3 for the lowest.

Business dynamics diagrams at the lowest level also show the types of organisation that undertake the business processes.

Types of organisation are shown on bottom-level diagrams as light blue "swim-lanes" within which processes undertaken by that type of organisation are placed.

For clarity it has sometimes been useful to define a "super-type" organisation such as BSC Party. Links to such a super-type indicate that the processes are undertaken by all the types of organisation that are part of that super-type. For example: a Supplier "is a" BSC Party, the Transmission Company is also a BSC Party.

These "is a" relationships between organisations are shown in a set of linked Hierarchy diagrams. Each of these organisation hierarchy diagrams shows the sub-types of a particular "super-type" of organisation.

The model also includes a set of Data Flow diagrams showing data interfaces between the Business Processes identified in the Business Dynamics diagrams.

Data Flow diagrams represent the flow of data between Business Processes and Data Stores representing defined data interfaces.

The data interfaces shown in the Data Flow diagrams are those defined in the BSC Data File Catalogue. They include both Part 1 (interfaces between Service Agents and BSC Parties) and Part 2 (interfaces between Service Agents) interfaces.

Data Flow diagrams are not arranged in a hierarchy of processes. Each diagram shows the group of interfaces associated with a particular Service Agent.

The structure of the data interfaces are shown by a set of Entity-Relationship diagrams; one for each computerised Data Store on the Data Flow diagrams.

These Entity-Relationship diagrams show groups of data items (Entities) and how they relate to each other in the Data Store concerned.

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Semantics of Business Dynamics Diagrams

Business Dynamics diagrams represent flows of events through business processes.

Business Processes are shown as yellow rectangles connected by arrows.

Arrows between processes represent internal events that occur as a result of one process and that trigger the next.

On the lowest level Business Dynamics diagrams, external events start a process sequence and external results terminate a sequence.

External events and results are defined as events/results that are external to the domain of the Balancing and Settlement Code.

External events are shown as dark green pentagons and external results are red.

Events do not carry data. (Data flows between processes are shown on data flow diagrams.)

For the sake of readability, external events and results are omitted from the higher level Business Dynamics diagrams.

Within a level of the hierarchy, Business Dynamics diagrams are connected together by "output" and "input" connectors. An output connector on one diagram will have one or more equivalent (with the same name) input connectors on other diagrams.

Connectors retain a semantic meaning since a matched pair of connectors shows an event flow between processes on different Business Dynamics diagrams. Since the modelling tool does not allow an output connector to be the match of an input connector on the same diagram, this rule enforces a semantic-based structure on the diagram hierarchy.

Input connectors are shown as light green pentagons and output connectors are pink.

NB Due to a fault in the modelling software the External Results and Internal Events and Results (Input and Output Connectors) are mislabelled as "External Events" when 'hovering' over the object and on the object details page.

An exclusion arc links event flows in an "exclusive-or" relationship and indicates that the result of the process will be either one or the other event.

An exclusion arc is drawn as a bold square arc across the relevant event-flow arrows.

A solid arrow head on a connector indicates a mandatory event flow whilst an unfilled arrow head shows an optional event flow (usually associated with an exclusion arc).

Optional event flows are labelled with the condition under which they are produced. Event flows joined by an exclusion arc are always optional.

Where connectors join before connecting to a Process or a Result this implies an AND relationship between the events; both events must occur to trigger the Process or produce the Result.

For Organisations that are super-types represented by a hierarchy diagram, the "swimlane" is marked with a dot at centre bottom.

Example of an Business Dynamics Diagram

Model consistency

The following consistency checks have been applied to all Business Dynamics diagrams.

A: Overlaps

B: All objects are connected

H: Optional connectors must have conditions

I: There is at least one mandatory result

J: There is at least one start event

L: Processes must be linked to at least one organisation

M: Processes must be linked to only one organisation

N: Processes, at the lowest level, must lie within an organisation

O: Processes must be linked to all overlapped organisation

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Semantics of an Organisation Hierarchy

Organisation Hierarchy diagrams illustrate the hierarchical relationships between different types of organisation.

Organisation types on an Organisation Hierarchy are shown as light blue ellipses.

The sub-type / super-type relationship between organisation types is shown by a hierarchy line labelled "is a". This signifies that the organisation types connected to the bottom of the line are sub-types of the organisation type connected to the top.

In some instances, a single line between organisation types shows a relationship other than a sub-type / super-type relationship. The label on the line indicates the type of relationship shown.

Sometimes different instances of the same type of organisation may be linked in the same process diagram, e.g. old and new Supplier.

Organisation types marked with a dot at centre bottom are themselves super-types that are represented by a subsidiary hierarchy diagram.

Example of an Organisation hierarchy

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Navigation of the BSC Business Process Model

The model represented on this web-site is designed for ease of navigation. The advantage of a model of this type is to enable the user to explore the Electricity Trading Arrangements by following a chain of ideas. There are, therefore, numerous ways in which the model can be traversed.

Navigation around diagrams

The most natural way to navigate around the model is to start with the top-level Business Dynamics diagram (the overview diagram) and then to drill down through the levels of the model to gain more and more detail on the business processes illustrated. To facilitate this, a click on the dot at centre bottom of a high-level process will display the next level diagram showing the flow of events through its sub-processes. Similarly, a click on the dot at centre bottom of a super-type organisation will display the hierarchy diagram defining the sub-types of that type of organisation. And a click on the dot at centre bottom of a Data Store will display the structure diagram showing the structure of the content of that Data Store.

Another way to navigate through the diagrams is via the Diagram Hierarchy page. This contains an indented list of the Business Dynamics diagrams in the model showing a "vertical" view of the decomposition hierarchy. Starting with the overview diagram, it lists the level 1 diagrams representing the processes it contains, the level 2 diagrams representing the processes contained in the level 1 diagrams, and the bottom level (level 3) diagrams representing the processes contained in the level 2 diagrams.

This page also contains: an indented list of the Organisation hierarchy diagrams; a list of the Data Flow Diagrams and a list of the Structure diagrams corresponding to each Data Store. You can access any diagram in these lists directly by clicking on its name.

Whether you access the Business Dynamics diagrams by drill-down or directly, you can then traverse the model horizontally by following a chain of events. To do this you can follow the relationships between input and output connectors on different Business Dynamics diagrams.

All diagrams are accompanied by a "navigation page" describing the way objects in the diagram interact with each other. A click on any event, result or input or output connector in a Business Dynamics diagram will take you to that object’s entry in this page. The entry includes a list of all the other diagrams on which that connector appears (as either input or output). A click on a diagram name in this list will display that diagram.

Note: If you have difficulty reading the name of an object in a diagram, 'hovering' the cursor over the object box will bring up the name of that object.

Navigation via object details

Every object in the model is fully described in its object page. These descriptions can be accessed from:

within the navigation pages by clicking on the object’s name;

from lists of all processes, organisations, events and applications in the model accessible from the index page.

The object details include cross-references to all diagrams in which the object appears and to all other objects with which they are associated. These cross-references open up further possibilities for navigating the model. For instance, if you want to follow a chain of events from a particular external event, the external event’s details will allow you to access a diagram on which it appears and then to follow the event flows across diagrams as described above. If you want to study the scope of a particular type of organisation or application, their details will give you access to all the processes in which they are involved and the diagrams on which organisations appear.

The descriptions of high-level processes, super-type organisations and data stores on their object pages include a "Is further detailed on " link which provides an alternative means of drilling down to the detail diagrams associated with these objects.

The lowest level of detail available on business processes is the process details of elementary (level 3) business processes. These details include references to the source documents from which the model was derived, providing a link from this Business Process Model of the Balancing and Settlement Code to the relevant BSC Sections and BSC subsidiary documents.

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