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. The 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. Use cases represent the interfaces that
a system makes visible to external entities and their interrelationships. It
has following components
a) Use case name
b) Brief
Description / Goal: what is to be achieved?
c) Flow of events
for <name> use case
d) Preconditions:
what the situation must be before the use case can take place
e) Main Flow: the
basic successful flow of events
f) Sub Flow (if
applicable): subordinate flows
g) Alternative flows:
variations in business conditions
i) Trigger: the
event that causes the use case to happen (usually by an actor)
