ISO/TS 20022-5:2004 describes the activities of "ISO 20022 reverse engineering" from the point of view of the user who wants to verify that the business functionality, covered by his own Industry Message Set, is covered by ISO 20022 compliant Business Transactions and Message Sets. It is not an attempt to define a"methodology" for reverse engineering.

ISO/TS 20022-5:2004 describes the following set of required activities:

• extract relevant information from existing Industry Message Sets and compare it to the related information in the ISO 20022 Repository;
• use the results of this comparison for the development of ISO 20022 compliant Business Transactions and Message Sets;
• submit the resulting update requests to the Registration Authority;
• prepare the migration to the ISO 20022 compliant Business Transactions and Message Sets.

The main objectives of the "ISO 20022 reverse engineering" are as follows:

• capture the industry knowledge covered by existing Industry Message Sets;
• build upon former standardization efforts in the industry when building ISO 20022 compliant Business Transactions and Message Sets;
• ensure that the resulting ISO 20022 compliant Business Transactions and Message Sets fully cover the business scope of existing Industry Message Sets;
• maximize interoperability between existing Industry Message Sets and ISO 20022 compliant Business Transactions and Message Sets;
• support the migration from existing Industry Message Sets to ISO 20022 compliant Business Transactions and Message Sets.

ISO/TS 20022-5:2004 gives some specific terms that are used in the document. It then describes the major activities that will be conducted during reverse engineering and also describes at a high level the resulting deliverables. A detailed workflow is presented, explaining all activities, inputs and outputs. Finally, a detailed description of the Convergence Documentation is given in an appendix.