Conceptional Problems of Transaction-based

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Conceptional Problems of Transaction-based Modeling and its Implementation in SimEvents 4.4 Lars Austermann*, Peter Junglas, Jan Schmidt, Christian Tiekmann PHWT Vechta, Schlesier Str. 13, 49356 Diepholz, Germany; * [email protected]

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Abstract. Transaction-based modeling is a widely used graphical method for modeling discrete event systems, a recent implementation being SimEvents from Mathworks. Though it is applicable to a wide range of problems, it has its specific drawbacks. Some of them are connected to the basic abstractions of the method, others are related to the specific program used. By implementing a few different standard examples, we will show some of these shortcomings together with possible workarounds. This should be pointed out, when teaching this method to new users, but additionally has to be taken into account, when building a new transactionbased library or corresponding blockset.

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Problems of Transaction-based Modeling and its Implementation

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Figure 1: Example with concurrent events.



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 Figure 2: CPU component of the ‘timeshared’ example.

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Problems of Transaction-based Modeling and its Implementation

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 Figure 3: Shuffle queue component of the ‘multiteller’ example.

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 Figure 4: Clone queue component of the ‘multiteller’ example.

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Figure 5: Change Stock component of the

Figure 8: Simple test model for accumulating timers.

‘supply chain’ example.

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 Figure 6: Storage component of the ‘supply chain’ example.

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 Figure 7: Accumulation of times in a PauseCTimer component.

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Austermann et al.

Problems of Transaction-based Modeling and its Implementation

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 Figure 9: Component EntityMeanMax for accumulating entity data.

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