Xiao Liu PhD Thesis.pdf - Faculty of Information and Communication ...

the previous one and the service provider re-evaluates the consistency state, until it
reaches or is above the minimum probability threshold.
In contrast, the probability oriented negotiation process begins with the user’s
initial suggestion of a probability value of α % , the service provider evaluates the
execution time R(SW
) of the entire workflow process SW by the sum of all activity
n
durations as ∑ w i ( µ i + λσ i ) , where λ is the α % percentile. If R(SW
) is above the
i=
1
maximum upper bound constraint of max(SW ) for the user, the probability value
needs to be adjusted, otherwise the negotiation process terminates. The following
process is the iteration that the user proposes a new probability value which is lower
than the previous one and the service provider re-evaluates the workflow duration,
until it reaches or is lower than the upper bound constraint.
Figure 5.6 Negotiation Process for Setting Coarse-Grained Temporal
Constraints
As depicted in Figure 5.6, with the probability based temporal consistency, the
time oriented negotiation process is normally where increasing upper bound
constraints are proposed and evaluated with their temporal probability consistency
states until the probability is above the user’s bottom-line confidence, while the
probability oriented negotiation process is normally where decreasing temporal
probability consistency states are proposed and estimated with their upper bound
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