Usecase describes the sequence of actions that a system perform to validate functional requirements.

Usecase ID Usecase Name Summary Priority Preconditions Postconditions Flow events

Use Case:

Use case is prepared by Business Analyst in the Functional Requirements Specification (FRS) whish is nothing but a steps are given by the customer. Designed before the Project started.

use case defines a graphical notation for use cases but it refrains from defining any written format for describing use cases in detail. Many people suffer under the misapprehension that a use case is its graphical notation (or is its description). While the graphical notation and descriptions are important they are documentation of the use case -- a purpose that the actor can use the system for.

The true value of a use case lies in two areas:

• First the written description of system behavior regarding a business task or requirement. This description focuses on the value provided by the system to external entities such as human users or other systems.

• Second the position or context of the use case among other use cases. As an organizing mechanism a set of consistent coherent use cases promotes a useful picture of system behavior a common understanding between the customer/owner/user and the development team.

It is common practice to create supplementary specifications to capture requirement details that lie outside the scope of use case descriptions. Examples of these topics include performance scale/management issues or standards compliance.

The diagram on the right describes the functionality of a simplistic Restaurant System. Use cases are represented by ovals and the Actors are represented by stick figures. The Patron actor can Eat Food Pay for Food or Drink Wine. Only the Chef actor can Prepare Food. Note that both the Patron and the Cashier are involved in the Pay for Food use case. The box defines the boundaries of the Restaurant System i.e. the use cases shown are part of the system being modelled the actors are not.

Interaction among actors is not shown on the use case diagram. If this interaction is essential to a coherent description of the desired behavior perhaps the system or use case boundaries should be re-examined. Alternatively interaction among actors can be part of the assumptions used in the use case. However note that actors are a form of role a given human user or other external entity may play several roles. Thus the Chef and the Cashier may actually be the same person.

Three major relationships among use cases are supported by UML. The UML standard describes graphical notation for these relationships. In one form of interaction a given use case may include another. The first use case often depends on the outcome of the included use case. This is useful for extracting truly common behaviors from several use cases into a single description. The notation is a dashed arrow from the including to the included use case with the label include . This usage resembles a macro expansion where the included use case behavior is placed inline in the base use case behavior. There are no parameters or return values.

Hi

Use case it a simple way to express the functional expression. Use case are prepared by the business analyst .Based on the use case the test case are written The following are the item which appear in the use case

• Use case id
• Use case name
• Summary
• Priority
• Pre condition
• Post condition
• Flow event