The Means End Link indicates a relationship between an end and a
means for attaining the end. Each means end link provides a different
mean for attaining the end. Whenever there are different ways to
achieve a goal, the means end link should be used to represent this
relationship, which acts as a logical ‘OR’ between the different ways
(means) of accomplishing the goal. The Means End Link is graphically
represented with an arrow, where the arrowhead points from the means
to the end.
In the online booking example, the goal is receive some confirmation of
the booking. There are 2 possible means of achieving this goal –
receive an e-mail or send a letter, but only one need be implemented.
The means is usually expressed in the form of a task, since the notion
of the task embodies ‘How’ to do something. On the other hand, the end
can be any node such as goal, task, resource. For the case of a soft
goal as an end, the Contribute To Soft goal link is defined later.
Although the above restrictions are not defined in the i* literature, we
recommend that they should be followed. However, the modeller is free
to use any of the possible means end links, but the reasoning of the link
should always be carefully validated
Reference: Reference: Neil Maiden (2011) Requirements Engineering Lecture Notes