1 files changed, 167 insertions, 0 deletions
diff --git a/usth/ICT2.7/P2L2 OO Software Engineering and UML Subtitles/26 - Use Case Diagram: Actors - lang_en_vs5.srt b/usth/ICT2.7/P2L2 OO Software Engineering and UML Subtitles/26 - Use Case Diagram: Actors - lang_en_vs5.srt
new file mode 100644
index 0000000..4d80c61
--- /dev/null
+++ b/usth/ICT2.7/P2L2 OO Software Engineering and UML Subtitles/26 - Use Case Diagram: Actors - lang_en_vs5.srt
@@ -0,0 +1,167 @@
+1
+00:00:00,110 --> 00:00:02,320
+Now, let's look at use cases in a little more detail.
+
+2
+00:00:02,320 --> 00:00:05,480
+And start by defining exactly what an actor is. An actor
+
+3
+00:00:05,480 --> 00:00:08,710
+represents an entity, which can be a human or a device,
+
+4
+00:00:08,710 --> 00:00:12,750
+that plays a role within my system, so that interacts with my
+
+5
+00:00:12,750 --> 00:00:15,660
+system. It's some entity from the outside world, with respect to
+
+6
+00:00:15,660 --> 00:00:18,510
+my system, that interacts with my system. It is important to
+
+7
+00:00:18,510 --> 00:00:21,750
+clarify that an entity can play more than one role. For
+
+8
+00:00:21,750 --> 00:00:25,240
+example, you might have somebody working in a bank that can be
+
+9
+00:00:25,240 --> 00:00:28,400
+both an employee of the bank, or a customer of
+
+10
+00:00:28,400 --> 00:00:31,280
+the bank, depending on how it interacts with the banking
+
+11
+00:00:31,280 --> 00:00:34,360
+system. And, obviously, more than one entity can play the
+
+12
+00:00:34,360 --> 00:00:37,570
+same role. Using the same example, we can have both an
+
+13
+00:00:37,570 --> 00:00:40,350
+employee of the bank and just a regular customer, playing
+
+14
+00:00:40,350 --> 00:00:43,280
+the role of the customer. So again, it all depends on
+
+15
+00:00:43,280 --> 00:00:46,120
+what the entity does, how the entity interacts with the
+
+16
+00:00:46,120 --> 00:00:50,150
+system, what kind of functionality of the system the entity uses.
+
+17
+00:00:50,150 --> 00:00:53,270
+And finally, actors may appear in more than one use case.
+
+18
+00:00:53,270 --> 00:00:55,930
+So it's fairly normal for the same actor to interact with
+
+19
+00:00:55,930 --> 00:00:58,540
+the system in different ways. And therefore, to appear in more
+
+20
+00:00:58,540 --> 00:01:00,710
+than one use case. Just think about the use cases in
+
+21
+00:01:00,710 --> 00:01:04,230
+scenarios of usage. If the same actor can interact with the
+
+22
+00:01:04,230 --> 00:01:07,440
+system in different ways, that actor will appear in multiple use
+
+23
+00:01:07,440 --> 00:01:11,210
+cases. Now let's go back to the description of our course
+
+24
+00:01:11,210 --> 00:01:15,140
+management system, and see how we can identify actors in the system.
+
+25
+00:01:15,140 --> 00:01:17,500
+And as we did for the class diagram before, I encourage
+
+26
+00:01:17,500 --> 00:01:20,160
+you to stop the video and try to identify the actors
+
+27
+00:01:20,160 --> 00:01:22,301
+in the system yourself, before I do it.
+
+28
+00:01:23,475 --> 00:01:27,250
+If we look at the description, we can see that, for example, the Registration
+
+29
+00:01:27,250 --> 00:01:30,890
+Manager is clearly an actor for the system. Students are actors
+
+30
+00:01:30,890 --> 00:01:34,400
+for the system. Professors are actors for the system. And notice
+
+31
+00:01:34,400 --> 00:01:36,060
+that we're not doing the same thing that we were doing
+
+32
+00:01:36,060 --> 00:01:38,360
+when identifying classes. Here we're identifying
+
+33
+00:01:38,360 --> 00:01:40,460
+entities that are from the outside
+
+34
+00:01:40,460 --> 00:01:43,090
+world, and have an active role in interacting with my
+
+35
+00:01:43,090 --> 00:01:46,830
+system. Again, Registration Manager, that we will just call registrar for
+
+36
+00:01:46,830 --> 00:01:50,660
+simplicity, students, and professors. So once we have identified the
+
+37
+00:01:50,660 --> 00:01:53,760
+actors for our example, we can simply draw them, using the
+
+38
+00:01:53,760 --> 00:01:56,550
+notation that we just introduced. So we have the registrar,
+
+39
+00:01:56,550 --> 00:01:59,830
+and notice how for every actor we clarify the role that
+
+40
+00:01:59,830 --> 00:02:02,450
+the actor plays. We have the professor, and we have
+
+41
+00:02:02,450 --> 00:02:05,480
+the student. So here, these are the three actors that we
+
+42
+00:02:05,480 --> 00:02:07,000
+identified for our system.