©Net Objectives, 2002
NetObjectives
35
MSS as a Series of Steps
nEach
Step is one of:
nAn
Interaction
nA
Validation
nAn
Internal Change
nExample:
Withdraw Cash
1.The ATM Customer
selects an account to withdraw from, and enters an amount to withdraw, in multiples of $20.
2.The ATM Machine
verifies that there is enough money to dispense.
3.The ATM Machine
notifies the Main Banking System of the Customer Account and amount being withdrawn
4.The Main Banking
System returns the new balance and (if appropriate) the fee amount.
5.The ATM Machine
dispenses the cash and updates the receipt.
*The ATM Machine logs
each step of this transaction.