Sketch use-case diagrams to show participants in use-cases- Software Engineering
Starting with ‘make a name’ and ‘finish a name’, draw use-case diagrams to show the participants in these use-cases. Then draw different use-cases to say what different vital interactions these participants may need with one another, or with different events.
Write postconditions for ‘make a name’ and ‘finish a name’. Use this process:
1. Write the postcondition informally, in customers’ phrases.
2. Draw a earlier than/after snapshot to illustrate the adjustments proven in your postcondition. Use an affiliation or attribute to symbolize every truth referred to in the postcondition.
three. Write a definition of every attribute or affiliation: ‘when this affiliation hyperlinks objects A and B, it represents the truth that…’.
four. Restate the postcondition in phrases of the adjustments illustrated in the snapshot.
5. If there are different potential outcomes, embrace these in the postcondition, with the Helpance of one other snapshot if obligatory.
6. Write a precondition: what have to be true for this use-case to happen?
7. Add timing necessities to the use-case, the place acceptable.
eight. Replace the sort mannequin, if obligatory.
Statecharts
Draw a statechart for a Cellphone. The transitions must be use-cases. The states you affiliate with a Cellphone haven’t got to be data recorded throughout the Cellphone itself: for instance, you may need a ‘suspended’ state for telephones whose payments are unpaid. As analysts, we’ve not but determined the place this data may be saved, however it’s extra probably to be in the Billing Company than the Cellphone itself. However, your statechart can embrace it as a result of the data is related to the cellphone someplace in the world we’re coping with – and it definitely has an impact on the cellphone’s behaviour.
We’ll determine at a later design stage, the place to put the data. Take into account whether or not it may be extra helpful to draw a statechart for a Cellphone Service – that’s, the service supplied to a buyer by numerous organisations by means of a cellphone. A Cellphone Service has comparable states to a Cellphone; however a Cellphone Service might proceed by means of the alternative of a damaged Cellphone.
· For every state, write its definition (1) in pure language; (2) as a boolean perform of different attributes and associations of Cellphone (or PhoneService) in your mannequin. Chances are you’ll want to add new associations to the mannequin for this objective.
· If there are new use-cases you may have discovered, add these to the mannequin and draft pre/postconditions for them.
