The increasing degree of integration of navigation systems and of complexity of these systems place new requirements on their use, test methods and specifications. These systems (Integrated Bridge Systems, Integrated Navigation Systems, Track Control Systems) contain a large number of functionalities, which have hitherto been carried out by equipment and units clearly delimited from one another. The purpose of this study is to develop a framework for Integrated Navigation Systems that enables an equipment-independent description of the requirements in order to take account of the large range of existing systems as well as future developments. In Part A, the functions fundamental to navigation operations are identified. A hierarchical approach is used to identify the global process task, task areas, tasks, functionalities and, finally, elementary functions. In Part B, a model of the ‘integrated navigation’ process is derived from the functional analysis. With the aid of the model it is possible to identify functional dependencies and resultant error chains. A ‘three-dimensional network’ is developed that represents the information flows between the functional units. In Part C, requirements on the testing of Integrated Navigation Systems are derived from the functional model. Independent of specific technical implementations, the starting points are information flows. The requirements the functions place on their respective input information are identified. Furthermore, categorisation of the test requirements is undertaken. This paper is a shortened version of the ‘Integrated Navigation Systems scope and model’. The complete paper (183 pages) may be obtained from the authors.