RE: (ROSE) Question About Actors

[Couball, James]

Actors (usually) represent roles of things outside the system.  The thing (person, system, etc.) playing an actor role may sometimes also play a role of something inside the system.  However, the actor concept is always outside the system.   James. -----Original Message----- From: Richard Howlett [mailto:[EMAIL PROTECTED]] Sent: Wednesday, February 07, 2001 4:03 AM To: Rational Rose Forum (E-mail) Subject: Re: (ROSE) Question About Actors Hi,   <<IMHO an actor need not necessarily be an entity outside the scope of the system - they may in fact be part of it.>>   Actors are the source of events to which the system is being designed to react to. System/Actor goes together in the same way that concave/convex goes together - one can't exist without the other. To define the scope of the system under discussion (SuD) you must describe its actors, or you simply don't have a system. Now the scope of what is being modeled is important to consider. From the perspective of one subordinate system, other subordinate systems are actors. From the perspective of the user of the superordinate system the subordinate systems are internal system components.   -Richard ----- Original Message ----- From: Colin Gourlay To: 'Pankaj Chatterjee' ; Rational Rose Forum (E-mail) Sent: Wednesday, February 07, 2001 4:15 AM Subject: RE: (ROSE) Question About Actors Well I am fairly new to the UML world so the following may not be 100% accurate!   My understanding of an Actor is that it is something or someone that either gives value to or gets value from say a use case in which it is associated.   The actor may be a primary actor in that it initiates actions within the system under discussion or it may be a stakeholder (whereby it has a vested interested in the value of a given use case).   IMHO an actor need not necessarily be an entity outside the scope of the system - they may in fact be part of it.    Hope this helps   Regards   Colin       -----Original Message----- From: Pankaj Chatterjee [mailto:[EMAIL PROTECTED]] Sent: 06 February 2001 10:20 To: 'Rose Forum' Subject: (ROSE) Question About Actors Hello,   My understanding is that an Actor is an entity that is outside the scope of the system under consideration. They help us to define the scope that is outside the system as well as what is inside. Actors act upon the system but are not acted upon.   Is this a correct description or is there some thing untrue? Please also add the missing parts   Thanks   Pankaj