Use Case in Tool Case

Question

how we should create the use case diagrams, make a diagram encompassing all use cases or make several diagrams for each specific scenario.

Ex.: I have within the system several lines of work, part of stock, financial part, part of sale for customers. I create diagrams with all the use cases all mixed or do one for stock, do another diagram just for financial and so on?

Answer 1

This is not the most appropriate place to address this issue specifically, because the way it was put would become too broad, even though it is a very important subject.

You can use sites like UFCG.

If you create your use cases and feel some doubt regarding them, you can elaborate this specific question and post it here.

The issue of use cases is that you have to consider the actors, who are the users of the system.

The center of the system should be the users, so their use cases, be it in spreadsheet format or diagrams, should consider what actions each actor should perform and this must be exhaustive, that is, you should describe all use cases for all users or actors.

In fact, as an initial part of the requirements elicitation process, the use cases describe the functionalities of the system succinctly. Thus, each actor being linked to at least one action and one action to at least one actor, so that details that will be dealt with later in the process of elicitation of requirements are not present. It is a kind of overview of the system, so general, that for the lack of details is called, this part of the process of software engineering, of black box.

This is literally subject for more than one book. Requirements Engineering That’s where it all starts. Research by needs is what will give rise to the first models of the software, so all the actions that each actor should and can perform in the system should be made explicit in the simple use cases. (Example: Actor: HR Employee -> Vacation Registration - and all other actions that this employee can perform).