AIXM 5.1/5.1.1


AIXM 5.1.1 is fully compatible, at data set level, with the previous AIXM 5.1 version. This means that data can be converted forwards/backwards between the two versions without any data loss. Therefore, the two versions are presented together. The main objective for version 5.1.1 was to move the maintenance of the AIXM UML model to a new modelling environment (Sparx EA). On the same occasion, a few small corrections have been made to the XML Schema and the UML model. This was also the first AIXM version issued under the authority of the global AIXM Change Control Board (CCB), as explained in the Governance section of this site.

  AIXM 5.1.1 Specification [quick link -> AIXM 5.1.1 UML navigator]

►  AIXM 5.1 Specification [quick link -> AIXM 5.1 UML navigator]

Implementation advice

It is recommended to use the new AIXM 5.1.1 version as soon as possible for those users/implementers who are in one of the following situations:

  • if starting a new project using AIXM - because the new version solves some of the bugs identified in AIXM 5.1 schema. As AIXM 5.1.1 data sets can be fully backwards-forward mapped towards AIXM 5.1, the compatibility with the existing AIXM 5.1 system is ensured;
  • if further developing an existing AIXM 5.1 extension or if creating a new extension - because the support for building extensions is improved and better documented with the new version.
  • if having difficulties with the AIXM 5.1 schema when using the OGC WFS Schema, because of the incompatibility of the xlink versions - this issue is solved in the new version.

Summary of changes

The changes made in this version are fully detailed in the AIXM Change Descriptions approved by the AIXM CCB. The complete list of changes is provided below, grouped in four high-level categories:

  • Migration to Sparx EA, which by itself did not affect the UML model or the XML Schema. However, this has an impact on AIXM 5.1 extensions, which will need to be migrated to the new data modelling environment. Further details are provided in the AIXM Application Schema Development guidelines.
  • Alignment with the latest GML 3.2.1 specification with regard to the use of the XLink and GML XML Schema and update of the GML profile reference. The XLink schema, the GML schema and Metadata schema are no longer copied locally, they are referred to from their reference Web sites.


  • UML model corrections and improvements with no impact on the XML Schema (such as improved definitions, add missing association or role name, correct typing errors, etc.)


  AIXM-152   AIXM-155   AIXM-163
  • Small XML Schema corrections
  • corrections of a few typing errors in lists of values, such as spaces in the middle or at the end of the value;


  • add missing nilReason;


  • correct a pattern that blocked linking annotations with certain property names;
  • add a limited number of additional allowable values, such as "electric" type of aircraft engine.


  AIXM-147   AIXM-150  

The AIXM 5.1.1 XSD has been generated with a new script that ingests the AIXM 5.1.1 UML model from Sparx EA. In order to ensure that no unintentional changes have been made in this process, the final AIXM 5.1.1 XSD was put in a normalised form and compared word by word with the AIXM 5.1 XSD, in the same form. All changes have been identified and validated, as documented below:

Forward/backward mapping

The public AIXM repository on GitHub makes available two XSLT files that may be used to convert an AIXM 5.1 data set into a valid AIXM 5.1.1 data set and vice-versa. Each script is offered "as is", under a BSD license (as indicated in the heading of each file). They are not aimed to be used in an operational environment, but only as a demonstration that the full forward-backward mapping between AIXM 5.1 and AIXM 5.1.1 is possible.