use case

Use case

A use case is a methodology used in system analysis to identify , clarify , and organize system requirements . The use case is made ​​up of a set of possible sequences of interactions between systems and users in a particular environment and related to a particular goal . It consists of a group of elements ( for example , classes and interfaces ) that can be used together in a way that will have an effect larger than the sum of the separate elements combined . The use case should contain a all system activities that have significance to the users . A use case can be thought of as a collection of possible scenarios related to a particular goal , indeed , the use case and goal are sometimes Considered to be synonymous .

A use case ( or set of use cases ) has these characteristics :

• Organizes functional requirements

• Models the goals of the system / actor ( user ) interactions

• Records paths ( called scenarios ) from trigger events to goals

• Describes the main one flow of events ( also called a basic course of action ) , and possibly other ones, called exceptional flows of events ( also called alternate courses of action )

• Is multi - level , so that one use case can use the functionality of another one .

Use cases can be employed during several stages of software development , such as planning system requirements , validating design , software testing , and creating an outline for online help and user manuals

include

The inter - connectedness include use case shows that the original use case explicitly incorporates the behavior of another use case roomates is designated by the use case . Included use case never stands alone , but only a part of a larger use case that Followed . Connectedness include use case is in fact an example of the delegation - the set of a system of responsibility taken and captured in one place ( included use case ) - then the other part of the system ( use case to another ) introducing a new set of responsibilities for each when they need the functions of the use case .

Actor is something or someone who is outside the system and Participate in the activities of the system . Actors can be : End Users , hardware devices, and even other systems . Each use case is a complete series of an event occurrence , seen from the point of view of the actor .

the focus of a use case is to explain how to Achieve a purpose or goal . In software development , it takes a lot of use cases to define the scope of a system . the degree of formality of a system that was developed to Determine the level of detail required of a use case

Use Case should not dicampuradukan with the features of the system , a use case may be associated with one or more features of the system , a feature may terelasi with one or more use cases

Extend

Connectedness extend the use case indicates that the designated use case is an extension of use case behavior origin . Original use case can stand alone , but for certain conditions the behavior of the use case may be extended by the behavior of another use case . Expansion is used to the model the relationship part of the use cases that can be seen by the user as a behavior that can be selected from the system . Expansion of the relationship can also be used to model of the flow of separate sub that can only be executed under certain conditions . In the end , the expansion of the use case relationships to model of multiple streams that can be inserted in a certain point .

Usecase that I made is about facebook :

Users can see the new profile , create new profiles and edit their profiles .

Users perform activities such as :

a) Chat with friend

b ) Send message

c ) Delete message

d ) Clay notice

e ) Create a new ststus

f ) Search friend

g ) Confirm friend

h ) Remove status

i ) Publish status

j ) check in

then admin login, enter your email and password and if the password is wrong email and will return to the login menu and if the email and password is correct then it will go to the home.