in the development of the ICAO occurrence reporting system was reached in January 2004 with implementation of a new software system known as the European coordination centre for aviation incident reporting systems (ECCAIRS).( The transition to the software by the ICAO accident and incident data reporting (ADREP) system caps a decade of cooperation between the European Union(EU) and ICAO aimed at developing up-to-date taxonomies for occurrence reporting as well as the software tools needed for their implementation. The safety initiative can be traced to the late 1980s, when a European Commission study identified a need to integrate aviation safety data from the various reporting systems employed in member States. Consequently, the Joint Research Centre(JRC) in Ispra, Italy, began development of an automated incident reporting system that could collect information from various existing, incompatible sources. A secondary objective of the ECCAIRS project was to offer a database solution to those member States that did not have an automated system. After some research, the JRC determined that the most suitable approach to obtaining a scheme of classification on which to base the system was to use an already internationally known taxonomy in the field of occurrence reporting. The taxonomy of the ICAO ADREP system was chosen to fulfil this requirement. Development of the new ADREP 2000 taxonomy started in 1993 with them formation of the ADREP Study Group. The group's aim was to review the ADREP system, streamline the data collection process and enhance the classification of factors, in particular human factors. The ICAO's experience in operating such a system was used to provide guidance on the software tools required. At the same time, ICAO benefited from the software developed, since some of the specific initial draft taxonomy was completed by 1999 .Based on requests from States and international organizations, the use of the taxonomy was extended to air traffic management (ATM) occurrence reporting schemes. Inclusion of such data was greatly simplified by having access to the results of a systematic review of data items in ATM occurrence reporting systems which was published by Eurocontrol in 2000. Beginning in 1993, the ECCAIRS development team of the JRC worked with ICAO to develop a tool for occurrence data collection, storage, analysis and exchange. Cooperation proved fruitful for both sides. The ECCAIRS team gained expertise in the taxonomies used for occurrence reporting systems, and ICAO's experience in operating such a system was used to provide guidance on the software tools required. At the same time, ICAO benefited from the software developed, since some of the specification for the software were based on ICAO's needs. The development project encompassed the database tools to store the data, a browser to enter and retrieve occurrence information, graphing tools to facilitate analysis, data export and import capabilities to facilitate the sharing of data, and conversion tools to convert the old ADREP system reports and data obtained from States using other electronic databases. In addition, tools were developed to capture, maintain and distribute the taxonomies used in ADREP 2000. At ICAO's request, additional applications were developed to facilitate the generation of safety reports and to integrate an electronic library of final reports into ECCAIRS. Also, security measures were implemented in ECCAIRS to safeguard the confidentiality of the data. ICAO has used the data conversion tool developed by the JRC to convert its old ADREP data as well as to convert data originating from the U.S. National Transportation Safety Board (NTSB) system. This tool permits viewing of the mapping rules and facilitates use by taxonomy experts without requiring that they spend time on the detailed programming of the conversion rules. The taxonomy editor provided by the JRC has proven to be an essential tool in the maintenance of the ADREP 2000 taxonomy. It provides for the tracking of changes, documentation of the change history, comparisons of different versions, search capabilities and data manipulation. A derived version is used to assist in the translation of the taxonomy so that localized versions of the tools can be made available. The ECCAIRS system permits the sharing of analysis tools and a library of queries and of graph definitions among different users. The libraries developed by ICAO have been shared with States, permitting new users of the system to obtain a number of examples on which to build. As a result of a new EU directive on occurrence reporting in civil aviation, from July 2005 all EU member States will report aviation occurrences and will start to exchange information. To support the directive, the European Commission has made the ECCAIRS software available to its member States. The ECCAIRS system for the first time allows States to report safety data to ICAO electronically. Information on the data structures and taxonomies has been posted at the ICAO website. ECCAIRS 4 software is available to State aviation safety authorities and investigation bodies at no cost. ICAO accepts reports in the ECCAIRS data exchange format for inclusion in the ADREP database. Now that the ECCAIRS system is operational at ICAO, the next step is to concentrate on enhancing the system's capability to handle data found in other aviation safety reporting systems such as the ICAO bird strike information system (IBIS(.In addition, related guidance material is being developed. The close cooperation and sharing of expertise between the users of the occurrence reporting system, ICAO and the developer of the ECCAIRS system, has eliminated the need for multiple software development and also ensured the compatibility of the software and data. It has also greatly reduced the cost of updating occurrence data reporting systems managed by States and by ICAO.