Week 5: Usecases Flashcards
What SDLC Core process is usescase created in
3: investigating sys requirements
what is a use case
an activity that the sys performs in response to a request by a user
what type of requirements do use cases define
functional
what is it called when analysist decompose the sys into a set of use cases
functional decomposition
what are 2 techniques for identifying use cases
user goal technique
event decomposition technqiue
how are usecases named
verb noun
in general, how are usecases made with the user goal technique
identify all potential categories of users of the sys
interview and ask them to describe the tasks the comp can help them with
probe further to refine the tasks into specific user goals
in general, how are usecases made with the event decomp
identify the events that occur to which the sys must respond
for each event, name a usecase (verb-noun) that describes what the sys does when the event occurs
what are characterisitcs of an event
it occurs at a specific time and place, can be described, and should be remembeed by the sys
what are 3 types of events
external event
temporal event
state event(internal event)
what is an external event
an event that occurs outside the sys usually initated by an external agent or actor
what is a temporal event
an event that occurs as a result of reaching a point in time
what is a state event(internal event)
an event that occurs when something happens inside the sys that triggers the need for procesing
what are benefits of the event decomp technique
events are broader than user goal, capture temporal and state events
what is an EBP
elementary business process
A fundamental business provess performed by one person in one pleace in response to a business event
what is a use case diagram
a UML model used to show use cases and their relationship to actors
what is an actor in a UML
the end user
are users ever inside the automation boundary of the sys
no, but they may be part of the manual portion of the sys
what is the automation boundary
the boundary between the computerized portion of the application and the users who operate the applcation
what is the sys boundary
the seperation between the sysm and its enviorment which I/O must cross
in use case diagrams, how is an actor depicted
a stick fig
in use case diagrams, what do lines from actors to usecase show
show which actors participate in use cases
in use case diagrams, what is this black box
the automation boundary
how many use case diagrams are drawn
drawn for each subsystem
drawn for each actor
what is an actor
what do associations between an actor and a use case signify
what does it mean when more than one actor points to one use case
the use case is associated with more than one role
can the sys clock be the primary actor of a usecase
Are usecases the “what” of the system or the “how” of the sys
what
achieves business goal, technology neutral
must a usecase leave the sys in a stable state
yes
what are 3 relationships between use cases
include
extend
generalization
what is the include relationship
where one usecase is stereotypicly included within the other use case
which way does the arrow point in an include relationship[
arrow points to subroutine
should the dotted line between usecase with an include relationship indicate data or a flow
no
what does a usecase extend relationship do
extends a use case by adding new behaviors
can you have chains of “extends”
yes
what is generalization between use cases
child use case inherits props and behavior of parent use cases and may ovverride the behavior of parent
what could all these be generallized to
search for books
what does a brief usecase description do
gives enough detail for very simple use cases
what is a fully developed use case description
what do fully developed use case descriptions include
use case name(verb noun)
scenario(if needed)
triggering event
breif description
actors
related usecases
stakeholders
pre/post conditions
flow of activities
except concdtions
is “user” or “admin” good actor names
no, too abstract
3 magic questions when writing use cases
what perspective do you write use cases from and in what tense
the users, present
what does CRUD stand for
create
read/report
update
delete
used in DB context
how is CRUD useful with usecases
look at each type of data and verify that usecases have been identified that
create
read/report
update
delete/or archive the data
what happens when a usecase has only one pathway
the granularity of the usecase is much to fine
what does functional entitlement mean
there is a clear mission defined for the usecase
what does each step consist of in a use case
involves an event and a response:
the users action and the systems reaction or vice versa
what 2 things can a use case be triggered by
a sys initiated event to which the user repsonds
a user initiated event that the sys has to respond to
