The AIXM UML model includes basic constraints expressed as lists of values, range of values, patterns. These are enforced in the AIXM XML Schema. More complex constraints, such as dependencies between the values of different attributes (sometimes in different classes), detection of out of range values, mandatory properties for specific data usage, data quality requirements (resolution, accuracy), etc. are not included in the UML model and do not appear in the XML Schema. Thus the need to document such more complex constraints as “business rules”.
In the earlier versions (up to AIXM 4.5), such business rules were part of the model. However, the experience accumulated through implementation shows that such rules are not equally applicable in all AIXM communities. The most obvious example are mandatory properties for AIXM features. For flight planning applications, there is no need for the frequency/channel of a navigation aid. On the other side, such attributes are mandatory for data sets intended for air navigation applications. Therefore, the aim of the AIXM Business Rules project is to maintain an exhaustive set of candidate AIXM business rules, from which profiles for a particular application or set of applications can be extracted.
The Semantics of Business Vocabulary and Business Rules (>>> SBVR) standard is used for the writing of the AIXM business rules in relation with the AIXM UML logical data model, which provides the "business vocabulary". The following document describes the concepts and conventions applied in the writing of the AIXM business rules:
Work in progress
An initial set of AIXM 5.1 business rules was published in 2010, in the form of an Excel file containing around 1500 draft rules. That initial draft is being reworked and expanded taking into consideration:
- the feedback from trials and test implementations (OGC test beds, European AIS Database, other local implementations);
- the work done on the AIXM Coding guidelines for the new ICAO data sets, in particular the AIP Data Set
- the needs of various stakeholder communities for profiles of business rules, such as the EAD Profile which is developed for the European AIS Database (Release 12).
This update is taking place in steps. The latest version of the AIXM Business Rules data set is provided through the link below. It contains around 1800 rules, in particular rules applied by the European AIS Database (EAD) for AIXM 5.1 data providers and rules that support the >>> ADQ requirements for data accuracy and data resolution.
Note: Each set of business rules is applicable to a specific AIXM version and each rule has a unique identifier that includes the AIXM version. The current set is applicable to AIXM version 5.1. However, the same rules can be used with AIXM version 5.1.1, as there are no differences between the two AIXM versions that would make one of the rules inapplicable.
The next version is scheduled for December 2017 and it will include with priority:
- a new Profile, for the rules that are relevant for the provision of an AIP Data Set in AIXM format;
- additional rules necessary for ADQ compliance, in particular constraints on the timeliness of the data (AIRAC cycle requirements);
- draft rules derived from the Digital NOTAM Specification (coding scenarios);
- possibly, a small number of additional rules that might be found necessary for the EAD_Error profile, which are necessary in order to ensure that the AIXM 5.1 data selected for backwards conversion to AIXM 4.5 can actually be converted. This concerns EAD Release 12;
For information, previous working versions of the AIXM 5.1 Business Rules set are provided here:
► [2017/02] AIXM 5.1 - Business Rules (ver. 0.7.2)
► [2015/09] AIXM 5.1 - Business Rules (ver. 0.5)