If in the interaction graph of entity Sue we look at the arcs that relate to

If in the interaction graph of entity sue we look at

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If in the interaction graph of entity “Sue” we look at the arcs that relate to the canceled “lab” Proclet in- stance (Figure 9.19b) then we see that the arc from the “(lab,Sue 25/01,send report)” node to the “(visit,Sue 10/02,receive)” node has the state “unproduced”. This means that no performative has been sent yet from the “send report” task to the “receive” task of the second visit. Note that the “send report” task is linked with an outbox interaction point. As a consequence, we have an exceptional situation as the respective performative will never be sent at any time in the future, i.e. the defined interaction will never occur. Subsequently, the arc from the “(lab,Sue 25/01,send report)” node to the “(visit,Sue 10/02,receive)” node transitions to the state “failed” (Figure 9.19c). Moreover, similar to the previous exception, a human actor may extend the interaction graph for “Sue”. As the exception occurred for the “lab” Proclet instance due to its cancelation, the graph may be extended by using the exception interaction point of the “lab” Proclet class (not shown in Figure 9.19a). Note that if the “lab” Proclet instance had been completed and no performative had been sent from the “send report” task (e.g. due to a choice in the process), then the same procedure as described above would be followed. Inbox Interaction Point Another exception that may occur in the context of canceling a Proclet instance is related to an inbox interaction point. This is illustrated in Figure 9.20. Here, for the first scenario, we assume that the “visit” Proclet instance for the second visit is canceled and that no tasks for it have been executed yet (Figure 9.20a). Also, for the “lab” Proclet instance we assume that no tasks have been executed. Looking at the interaction graph of “Sue” (Figure 9.20b), for the arcs that relate to the canceled “visit” in- stance we can see that the arc from the “(lab,Sue 25/01,send report)” node to the “(visit,Sue 10/02,receive)” node has the state “unproduced”. So, no performative has yet been sent from the “send report” task to the “receive” task of the canceled “visit” Proclet instance. Note that the “receive” task is linked with an inbox interaction point. So, we have an exceptional situation as the performative which still needs to be sent from the “send report” task can never be consumed by the “received” task, i.e. the defined interaction will never occur. Subsequently, the arc from the “(lab,Sue 25/01,send report)” node to the “(visit,Sue 10/02,receive)” node transitions to the state “failed” (Figure 9.20d). Also here, the interaction graph of “Sue” is offered for exten- sion. However, as the exception occurred for the “visit” Proclet instance as a consequence of its cancelation, the graph may be extended by using the exception interaction point of the “visit” Proclet class. In Figure 9.20c, a comparable situation is shown. Here, the corresponding interaction graph is presented when a performative is sent from the “send report” task that has not yet been consumed by the “receive” task of the canceled “visit” Proclet instance. Here also, due to the cancelation of the Proclet instance for the
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