Lecture 2 Flashcards
what is use case modelling?
use cases are operations that the user can perform against the system to produce something useful. sequence of interactions between the uses of a system and the system itself, to achieve a particular goal.
what are the 2 steps when working with use cases?
identify use cases and describing them
what are 3 ways to identify use cases?
-work with requirements statement, -consider business processes, -consider stakeholders
what is a use case diagram?
contain actors (people or system), relationship between actors and use cases, and relationship between use cases.
what is an unstructured format when describing use cases?
write use cases in plain english, only really useful as a brief note.
explain flow format
use case: name trigger/goal: actors: mainflow: (step by step, each step is successful and use case is complete) extension: describes OTHER conditions
what are the 4 issues with use case modelling?
repeating actions, conditional statements, pre-use case, post-use case
how do we ass repeating actions to use case?
- main flow: – repeat steps 3-4 until
- extensions: 5a. there are less than 3 subjects 1. abort
how do we add conditional statements to use cases?
-main flow: –if a do 6
6. njwbfdlwb fbwjdibfiw
–if b do 7-8
7. fdsnjfdsj fklf
8. njsdknf nfdskjfsd
or
extension:6a pay by cash
6b pay by card
how do we add pre-use and post-use cases to use case?
pre-use case: student has logged in (logged in is underlined)
post-use case: restore price after 24 hours(restore price underlined)
or main flow: –do step after 24 hours
4.system restore price (restore price underlined)
how do we specify when user can abort and how many attempts?
extension: 1-4a. if any user chooses to terminate the use case
1. abort
extension: 2.b. invalid id entered 3 times
