TFH Berlin Fachbereich Informatik Medieninformatik SA31: Systemanalyse / SWT1: Softwaretechnik 1 Wintersemester 2000/2001

Lab 6: Analysis

1. Consider a file system with a graphical user interface, such as Macintosh's Finder, Microsoft Windows Explorer, or Linux's KDE. The following objects were identified from a use case describing how to copy a file from a floppy disk to a hard disk: File, Icon, TrashCan, Folder, Disk, Pointer. Specify which are entity objects, which are boundary objects, and which are control objects.
2. Assuming the same file system as before, consider a scenario consisting of selecting a file on a floppy, dragging it to a Folder and releasing the mouse. Identify and define at least one control object associated with this scenario.
3. Arrange the objects listed in Exercises 1 and 2 horizontally on a sequence diagram, the boundary objects to the left, then the control object you identified, and finally, the entity objects. Draw the sequence of interactions resulting from dropping the file into a folder. For now, ignore the exceptional cases.
4. Examining the sequence diagram you produced in Exercise 3, identify the associations between these objects.
5. Identify the attributes of each object that are relevant to this scenario (copying a file from a floppy disk to a hard disk). Also consider the exception cases "There is already a file with that name in the folder" and "There is no more space on disk". What other exceptions could occur?
6. Consider a traffic light system at a four-way crossroads (e.g., two roads intersecting at right angles). Assume the simplest algorithm for cycling through the lights (e.g., all traffic on one road is allowed to go through the crossroad while the other traffic is stopped). Identify the states of this system and draw a statechart describing them. Remember that each individual traffic light has three states (i.e. green, yellow, and red).
   

The URL pointing to your report is due in my mailbox by 8:00 am the morning of your next exercise.