# Use case testing

###### tags: `Black Box Testing Tech` `ISTQB` `Software Testing` `SQA`

**Use cases are one way of specifying functionality as business scenarios or process flows.**
They capture the individual interactions between ‘actors’ and the system.
**An actor represents a particular type of user** and the use cases capture the interactions that each user takes part in to produce some output that is of value.
Test cases based on use cases at the business process level, often called scenarios, are particularly useful in exercising business rules or process flows and will often identify gaps or weaknesses in these that would not be found by exercising individual components in isolation.
**This makes use case testing very effective in defining acceptance tests because the use cases represent actual likely use.**

Well-defined use cases can therefore be an excellent basis for system level testing, and they can also help to uncover integration defects caused by incorrect interaction or communication between components.

>**USE CASES**
In a use case diagram (e.g. Figure 4.3) each type of user is known as an actor, and an actor stands for all users of the type. Use cases are activities carried out for that actor by the system. This is, in effect, a high-level view of requirements.
The diagram alone does not provide enough detail for testing, so we need some textual description of the processes involved as well.