The Strategic Rationale Model (SR) provides a more detailed level of modeling by looking "inside" actors to model internal intentional relationships. It is used to: (i) describe the interests, concerns and motivations of participants process; (ii) enable the assessment of the possible alternatives in the definition of the process; and (iii) research in more detail the existing reasons behind the dependencies between the various actors. Nodes and links also compose this model. It includes the previous four types of nodes (present in the SD model): goal, task, resource and soft-goal. However, two new types of relationship are incorporated: means-end that suggests that there could be other means of achieving the objective (alternatives) and task-decomposition that describes what should be done in order to perform a certain task.
In Figure we use the SR notation to detail the Store agent. Due to space limitation we now only comment some aspects. An interested reader can find a fuller description of the approach in [10]. The store is interested in attracting (new and old) clients (expressed by task node To Attract Customers). Several strategic decisions were taken in consideration and as a result the task was decomposed into five aspects (expressed by a task-decomposition link):
The need to offer reasonable prices (captured by software goal Good Prices). Two alternatives are considered for meeting this objective: to offer discount on selected items (softgoal Discount Price) or obtaining good deals by buying large quantities of popular CDs (softgoal Volume Purchase[Highs]),
To need to establish a courteous relationship between the store staff and its clients (represented by softgoal Friendly Staff). This is considered to be a way of meeting the quality of service expected by the client.
To define standard procedures for delivering CD (expressed by sub-task Delivery),
To be able to maintain a good stock of CDs (captured by sub-task Maintain Stock). This will also require the updating of the online information system. Hence the task dependency Update Stock between the Store and SmartCD actors.
To handle internet sales (captured by sub-task Sales by Web), which depends on the adequate software system, hence the goal dependency Process Internet Orders between the Store and SmartCD actors.
After some considerations, it has been agreed that the task of maintaining the stock needs to be further decomposed:
The overall objective is to have all available titles on stock (captured by goal Have all titles). If this is met, certainly the client will be very pleased (see the softgoal Good Variety between Client and Store actors),
Buying new titles (expressed by a sub-task Buy new releases),
Making sure that popular CDs are re-stocked (expressed by a sub-task ‘Replenish’).
At this point, we may stop the process of modeling the strategic dependencies of the CD store. We are already capable of understanding some issues of the application domain (the enterprise). We can then move to provide a detailed system specification.