Example: login to SIS
Monday, April 05, 2010
1:40 PM
Example: login to SIS
Two participants: user and SIS
Dance steps: 
User requests SIS page. 
SIS prints page on browser. 
Repeat until success: 
User enters Login name and Password and presses "login". 
SIS checks Login name and Password and 
succeeds if correct. 
In this case, the dance "ends" successfully. 
prints an error message and fails if the form is too old. 
In this case, user presses "back" and "refresh" and tries again.  
prints an error message if SIS is unavailable. 
In this case, user ends session and tries later. 
prints an error message if the password and login don't match. 
In this case, user presses "back" and "refresh" and tries again.  
End repeat. 
This example: 
Involves multiple entities 
Has multiple failure conditions. 
Results in a predictable state if successful.