Overview
Use cases describe domain processes in a structured prose format. One of the primary
objective of use cases is to identify the actors. An actor in a use case is an external
agent that uses or interacts with the system. There is one initiator actor and possibly
several participating actors. In a nutshell, use case
- Describe the sequence of events of an actor using a system to complete a process.
- Represent business or domain processes.
- Are a narrative description of a business process.
- Are expressed in structured prose.
- Are not directly related to object technology.
"A use case is our construct for a business process. It shows the course of events."
"A use case is a sequence of transactions in a system whose task is to yield a result of
measurable value to an individual actor of the system."
- Ivar Jacobson
Use Case Name : Login
Description : A banking customer will logon to the automatic teller machine,
and thereby gain access to their account, to conduct transactions.
Actors : Banking customer (initiator).
Type : Primary/Analysis
Related Use Cases : None.
Preconditions :
- All banking customers are legitimate Main Line Bank Customers.
- To limit scope of considerations, any numeric PIN will be accepted as the correct PIN
for a supplied bankcard.
- Hardware failures are deferred for later consideration.
Basic Course of Events :
- This use case begins when a banking customer inserts their bankcard into the automatic teller machine.
- The automatic teller machine (ATM) reads the bankcard and prompts the banking customer for their
personal identification number (PIN).
- The banking customer enters their PIN number.
- The ATM prompts for a transaction type.
Post Conditions :
None
Alternatives :
None
Use Case Name : Logout
Description : A banking customer ends their transaction with the ATM.
Actors : Banking customer (initiator).
Type : Primary/Analysis
Related Use Cases : None.
Preconditions :
- A banking customer has inserted a bankcard into the ATM.
- Hardware failures are deferred for later consideration.
Basic Course of Events :
- This use case begins when a banking customer elects no further transactions.
- The ATM returns the customer's bankcard.
Post Conditions :
Banking customer removes bankcard from the automatic teller machine.
Alternatives :
None
Use Case Name : Withdraw Cash
Description : A banking customer withdraws cash from their account.
Actors : Banking customer (initiator).
Type : Primary/Analysis
Related Use Cases : None.
Preconditions :
- A banking customer has successfully logged in and the system is
ready to apply transactions to their account.
- A banking customer can only withdraw $200 within a 24-hour period.
- Withdrawals are only allowed in $10 increments.
- One receipt will be printed for each transaction.
- The automatic tellr machine contains enough cash and receipts to successfully
complete any approved withdrawal.
- Hardware failures are deffered for later consideration.
Basic Course of Events :
- This use case begins when the banking customer elects to withdraw cash from their account.
- The ATM prompts for the amount to withdraw (in increments of $10).
- The banking customer enters the amout to withdraw.
- The ATM checks to see if the banking customer's daily limit of $200 has been reached.
- The ATM checks to see if the banking customer's account has sufficient funds to
complete the transaction.
- The ATM dispenses the requested cash to the banking customer and the customer's account in
the same amount as the cash dispensed.
- The ATM prints a transaction receipt.
- The ATM returns the customer's bankcard.
Post Conditions :
Banking customer removes bankcard from the automatic teller machine.
Alternatives :
