This part of ISO 24014 provides the basis for the development of multi-operator/multi-service interoperable public surface (including subways) transport Fare Management Systems (IFMSs) on a national and international level. This part of ISO 24014 is applicable to bodies in public transport and related services which agree that their systems need to interoperate. This part of ISO 24014 covers the definition of a conceptual framework which is independent of organizational and physical implementation. Any reference within this part of ISO 24014 to organizational or physical implementation is purely informative. The objective of this part of ISO 24014 is to define a reference functional architecture for IFMSs and to identify the requirements that are relevant to ensure interoperability between several actors in the context of the use of electronic tickets. The IFMS includes all the functions involved in the fare management process such as – management of media, – management of applications, – management of products, – security management, and – certification, registration, and identification. This part of ISO 24014 defines the following main elements: – identification of the different set of functions in relation to the overall fare management system and services and media from non-transport systems which interact with fare management systems; – a generic model of IFMS describing the logical and functional architecture and the interfaces within the system, with other IFMSs and with services and media from non-transport systems; – use cases describing the interactions and data flows between the different set of functions; – security requirements. This part of ISO 24014 excludes consideration of the following: – the technical aspects of the interface between the medium and the medium access device; – the data exchanges between the medium and the medium access device; NOTE – The data exchanges between the Medium and the Medium Access Device are proposed by other standardization committees.