Working towards the next version of the SWIM Supporting Material

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Working towards the next version of the SWIM Supporting Material

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The abstract to the SWIM Information Definition Specification states: This specification contains requirements for information definitions, meaning the formal descriptions of exchanged information, in the context of Initial System Wide Information Management (iSWIM). This contributes to semantic interoperability of information.

Role of the SWIM Information Definition Specification

The following diagram illustrates the role of the SWIM Information Definition Specification. In it:

  • Organisation A will exchange information with another organisation or organisations using services (following the SWIM concept)
  • It is important that the meaning of the information exchanged is understood by the different organisations (semantic interoperability)
  • An information definition is used to define the information
  • It is important that information definitions themselves are comparable
  • The information definition's content follows the requirements set out in the SWIM Information Definition Specification

This identifies some key topics to be discussed:

exchanged information - information exchange

The term information exchange is a well-established term in the ATM domain.  For the good understanding of the term it should be clear that this does not necessarily imply that an "exchange" takes place in the normal meaning of the word "exchange".

Information exchange is used in ATM to refer to processes that allow information generated at one location to be made available at one or more other locations.   The meaning is very broad, and makes no restrictions on the mechanism used to enable sharing of information, or how many parties might be involved in that.  It does not imply that if information is transferred from A to B then some "reply" back from B to A is always required.  In fact, it covers multiple ways of sharing information regardless whether between two or more parties. This can be confusing because the word "exchange" in normal usage means "an act of giving one thing and receiving another (especially of the same kind) in return".  This suggests that "information exchange" would imply a transfer of information from one party to another, followed by some other information being sent in return.   But that is only one possible style of "information exchange" in the way the term is used in ATM.

Semantic interoperability

Semantic interoperability is the ability of computer systems and organisations to exchange data with unambiguous, shared meaning.

The ATM Information Reference Model (AIRM) is a key part in facilitating semantic interoperability within the context of the modernised European ATM network. It is the common reference language for aviation information and data. The AIRM contains the civil and military information constructs relevant to ATM in support of information exchange via SWIM. The AIRM represents the ATM related aviation information constructs in a harmonised way.

The specification contains semantic correspondence requirements to ensure that information definitions conform to the semantics of the AIRM.

It is worth noting that the specification does not put requirements on the format or notation (such as Unified Modeling Language (UML) or Extensible Markup Language (XML) Schema) used in information definitions. Nor does it put requirements on the AIRM.

Information definition

Information definitions, the formal descriptions of exchanged information, are produced or reused by operational stakeholders. They act as the means whereby the exchanged information is clearly defined. This promotes a common understanding of the definition of the information between stakeholders. Examples of information definitions are:

  • the description of information exchanged by services,
  • standardised information exchange models,
  • data catalogues used to list details on the exchanged information, and
  • information exchanges captured as part of a business process model.

In addition to the semantic correspondence requirements, the specification contains general requirements for information definitions. These include, for example, the need for an edition and a reference date. These requirements cover the ability to discover and decide on the use of a particular information definition. They also cover the concepts contained in an information definition - the concepts define the exchanged information.

Requirements overview

The requirements contained in the specification are visualised below. The figure includes the requirement number (e.g. SWIM-INFO-001). It groups the requirements and gives a broad summary of the content of the requirement.

Some requirements (SWIM-INFO-001 and SWIM-INFO-002) apply to the information definition as a whole and are added at the top of the diagram.

SWIM-INFO-003 to SWIM-INFO-006 and SWIM-INFO-012 are applied once and define the content of the information definition. For example, SWIM-INFO-003 requires that a title, edition and reference date be given in order to identify the information definition.

The remaining requirements apply to all of the concepts in the information definition. These include the basic needs such as to name and define the concept. There is also a need to give a semantic correspondence statement for each concept. The semantic correspondence requirements (SWIM-INFO-013 to SWIM-INFO-019) explain how the concepts in an information definition are "related" to the AIRM concepts.

Initial System Wide Information Management (iSWIM)

The requirements for information definitions are to be seen in the context of Initial System Wide Information Management (iSWIM) in Europe.

Initial System Wide Information Management (iSWIM) is outlined in the European Union’s Pilot Common Project Regulation (PCP). Among other things, the PCP requires that service implementations in support of the listed information exchanges “be compliant with the applicable version of the ATM Information Reference Model (AIRM), the AIRM Foundation Material and the Information Service Reference Model (ISRM) Foundation Material

The specification can be applied in different contexts. It can be used to improve information exchanges between any organisation. Information definitions that follow the specification will have an increased chance of being interoperable.