Figure 1 presents the time budgeting process, and how it maps to the generic methodology. The Find timing properties and the Analyze timing properties tasks have been split into two subtasks each in order to illustrate the activities to be performed in these tasks in more detail. Moreover, the tasks Verify timing properties and Specify timing requirements have been renamed to better reflect their purposes in the context of this use case. The following paragraphs will describe the figure in more detail.
Figure 1 - Generic time budgeting methodology
The process outlined in Figure 1 is in general applicable on all abstraction levels. However, some of the tasks in Find timing properties and Analyze timing properties do not exist for all abstraction levels, or are less important. Figure 2 illustrates this relationship.

Figure 2 - The degree of presence of Find and Analyze timing properties tasks at different abstraction levels
The task Transform time budget influencing properties inherently requires that there exists a lower abstraction level from which properties can be transformed. For this reason, it is not present at the operational level. Since the vehicle level primarily focuses on the user’s needs and perception, the task is not very present at that level either, although it sometimes makes sense to peak at results from early implementation.
Time budget influencing properties can be assigned at virtually any level, although it is done to a lesser extent at vehicle level. The task Assign time budget influencing properties is not present at operational level as that level does not leave any room for design decisions.
The task Determine time budget influencing properties requires that there exists at least a structural model, and preferably also a behavioral model, to analyze. This does not exist at vehicle level. Although such models do exist on analysis level, they often do not contain sufficiently detailed information that it is possible to directly determine any time budget properties. Such cases are better suited for the task Extrapolate time budget influencing properties. However, that task both requires structural, and preferably also behavioral, models to start the extrapolation from, as well as lower abstraction levels as target for the extrapolation. These conditions do not hold for the vehicle and operational levels.
Since the vehicle level only should reflect the user’s needs and perception, possible influence from future functions should not affect the vehicle level’s model. Moreover, the operational level does not give rise to further time budget requirements. For these reasons, the task Estimate influence from future functionality does not occur on this abstraction level.
As time budgets are not specified on the operational level, the task Create time budget proposal is not present at that level.
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