Help Index When the Selection Tool is started, it is first necessary to choose a Viewpoint with which to work. All work begins with the Functional Viewpoint, and when that is complete and consistent, it may be used as the basis for one or more Physical Viewpoints. Once a Functional Viewpoint has been used to create a Physical Viewpoint, it is no longer possible to change that Functional Viewpoint; but it is possible to duplicate it, and change the clone. It is possible to stop using the Selection Tool at any point and to "continue previous work" or to "edit previous work". The former automatically continues from the point reached in the process at the end of the last session. The latter starts again from the beginning of the process, so it is possible to make changes to any part of the work done. To go from User Needs to the Physical Viewpoint of a particular application you are first assisted to carry out a number of steps to determine the sub-set Functional Viewpoint: * Selection of the User Needs - identification of the User Needs that define the service(s) to be provided. * Selection of the Functions - identification of the Functions that help to satisfy the selected User Needs (according to the cross reference provided by the Trace Table). * Selection of the Data Flows - identification of the Data Flows needed by the selected Functions. * Selection of the Data Stores - identification of the Data Stores needed by the selected Data Flows. * Addition of the Data Flows for Data Stores - identification of the additional Data Flows needed by the selected Data Stores. * Selection of the Terminators and Actors - identification of the Terminators and Actors associated with all these Data Flows. * Report of the Consistency Checks - identification of inconsistencies and errors in the resulting sub-set Functional Viewpoint (i.e. some of the Data Flows that are required by the selected Functions may not have a source or a target, and some Functions and/or Data Stores may not have any associated Data Flows at all). To correct them, it is possible to come back to the selection of Functions, Data Stores, and Terminators/Actors. This time it is possible to select from all the Functions, Data Stores, and Terminators/Actors comprised in the European ITS Functional Viewpoint. A Physical Viewpoint is created from one (only) of the Functional Viewpoints. Once a Functional Viewpoint has been used to create a Physical Viewpoint it is no longer possible to change that Functional Viewpoint, unless you duplicate it and changes the clone. To create a description of how the sub-set Functional Viewpoint can be deployed as a Physical Viewpoint, you are assisted to carry out the following steps: * Definition of Sub-Systems - identification of the physical locations (Sub-Systems) where Functions and Data Stores will be set. * Allocation to Sub-Systems - allocation of the Functions and Data Stores to physical locations (Sub-Systems). * Definition of Modules - division of the Sub-Systems into Modules. * Allocation to Modules - allocation of the Functions and Data Stores to Modules within the Sub-Systems. * Physical Data Flows - definition of the Physical Data Flows that pass between the Sub-systems, Modules and the outside world (represented by Terminators and Actors). Close