1 They commit to have their site available four 9's What's meaning of ' four 9's '?
2 Response time cannot exceed 10 seconds more than 20% of the time Response time cannot exceed 12 seconds, right?
3 Create a sequence diagram/collaboration diagram for each use case. There are 7 use cases: 1 Login, 2 Change Profile, 3 View Frequent Flyer Miles, 4 Prepare Itinerary, 5 Change Itinerary, 6 Price Itinerary, 7 Pay for Itinerary. 3.1 Can I ignore the previous three: 1 Login, 2 Change Profile, 3 View Frequent Flyer Miles? If I don't create sequence diagram for the three one, can I pass the exam? 3.2 'Price Itinerary' is included in 'Prepare Itinerary' and 'Change Itinerary'. Still need I create a sequence diagram for 'Price Itinerary'? four 9's
1. With four nines they refer to the systems availibility if I'm not mistaking. The system should be available 99.99% over 365 days.
2. I think that the 20% is related to the number of requests made. Creating customers, searching flights, paying for an itinerary. The delta between the total of the request and the respective reply may not exceed 10 seconds for 20% of them.
So, you gathered all the requests and you found 100 of them. You calculate the time between request and response for each request. You end up with 100 numbers varying from 2 to 34 seconds for example. To meet the requirements not more then 20 may exceed 10 seconds.
3. I think the assignment asks you to create a sequence for each supplied use case (and I think they refere to the actual use cases, and not the diagram). So you should at least deliver 4 use cases. If you do more, that should not be a problem.