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Guideline (Beginner,Concept) Don’t mix Goals and Tasks in the Means-Ends links.


This stable version of the Guideline Wiki Page displays the guideline as per the i* Style of the University of Toronto. Registered users can use 'Open Version' link right at the end of the guideline statement below to access the open version of this page


Guideline   (Beginner,Concept) Don’t mix Goals and Tasks in the Means-Ends links. Open Version


Discussion: Goals are different than Tasks, and therefore can’t be mixed in Means-Ends Links. A Goal is an Actor’s End desire, not a Means to achieve this End desire (Goal). In i* framework, An End desire (Goal) is achieved via a Task, which is a Means to achieve the End desire or a Goal. See Section 5.2 “Elements/Nodes” for more explanation about Goals and Tasks. Figure 1 depicts an example where the Means-Ends Links is allowed and where it is not. See the guideline in section 5.2.1 “Goals (Hard Goals)” for an example of using the Means-Ends Link and Task notations to indirectly decompose Goals to sub-goals.

Note: The i* Means-Ends Link notation is not to be confused with a similar notation used by Tropos methodology to denote an OR decomposition of Goals. Figure 2 (troposproject.org) depicts Tropos notation for both AND and OR decomposition notation. It can be noticed that Tropos allows direct decomposition of Goals to sub-goals. On the other hand, i* decomposes Goals into sub-goals indirectly using the Task notation as shown in Section 3 “Summary of i* Notation” and discussed in Section 5.4 “Decomposition Links”. The i* notation of Goal decomposition encourages the modeler to consider distinctions among Goals, Softgoals, Tasks, and Resources are each step of decomposition.


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Created by system. Last Modification: Tuesday 01 of April, 2008 18:35:17 GMT-0000 by samer.