If you strive to find a single technique that will allow you to represent all gathered information as system requirements. In fact, you need to give up this idea because such a comprehensive chart does not exist. The initial goal of structured analysis systems was to completely replace the classical functional specification with graphical diagrams and notation systems, more formal than textual comment. However, experience has shown that analysis models should complement – and not replace – the requirements specification written in the natural language.
The models of the visual representation include data flow diagrams (DFD), entity-relationship diagrams, (ERD), state-transition diagrams (STDs), also called state diagrams, dialog maps, use case diagrams. The notation systems usually provide a common, industry-standard language that is used by project participants. Of course, you can deliberately develop diagrams to supplement the opportunities for oral and written communication between the project participants, but it does not necessarily mean that users will interpret them identically. At the same time, it is impossible not to recognize the value of non-standard process modeling methods. One team used a tool to make a diagram for modeling temporary requirements concerning embedded software, with milliseconds used as units of measurement, instead of days or weeks. Technical writing services help to prepare adequate, comprehensible and timely content for any technical documentation.
These models are suitable for the development and study of requirements, as well as for creation of software. Whether you will use them for analysis or for design depends on the time frame and modeling objectives. Applying these diagrams to requirements analysis will allow you to model the subject area or create conceptual representations of the new system. They describe the logical aspects of data domain components, transactions and transformations, real-world objects and system state changes. You can create models based on textual requirements to look at them from different perspectives, or to derive detailed functional requirements from high-level models created relying on the information provided by users. In the development process, the models demonstrate how you intend to implement the system: the database that you plan to create, the object classes that you will illustrate with examples, and the code modules that you are going to develop.