Model for Queue statistics
This section covers the queues' statistics.
Queues are used to represent specific model dynamics, in which an entity has to wait for another entity.
A pictorial example would be:
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Imagine the daily operation of a barber shop.
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There are two barbers that are being entered into the waiting Barber-Queue at the beginning.
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In the morning there are no customers, the barbers are just sitting around and waiting (in the queue).
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Suddenly at 10 O’clock the first customer arrives and inserts himself into the customer-queue.
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Since there are no other customers, this customer gets removed from the queue instantly along with a barber from the barber-queue.
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Ten minutes later two additional customers enter the barber shop and the customer-queue.
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There is only one barber available, so the first customer from the customer-queue gets served.
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The other one must remain in the queue until one of the barbers is available again.
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This goes on until the shop closes.
Our queue statistics get updated every time an entity enters or leaves a queue. See the following model and its report for a detailed example.
Process description
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The "Controlling" process starts constantly each hour.
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It contains one activity that lasts between one and two hours.
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Additionally the activity sends a message to the "Marketing" process and terminates after that.
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Note that messages are sent once the activity has been reached.
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The Marketing process is as trivial as the one mentioned before.
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However, we constructed its simulation parameters in a way, so that we get significant queue-statistics in any case.
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To achieve this, we made the "Marketing" process start every two hours (Constant Distribution).
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Thus, the "Controlling" process always sends a message to the bottom pool’s activity, before any process instance can reach it.
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This means the message is being queued to be handled by a to-be process instance, that starts in the future (simulation time).
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See the report for the description of the resulting queue statistics.
| BPMN Element | Simulation Properties |
|---|---|
Start event "Controlling" |
Inter-arrival Time: Constant Distribution with value = 1 |
Start event "Marketing" |
Inter-arrival Time: Constant Distribution with value = 2 |
Activity "Send E-Mail to Marketing" |
Duration: Discrete Uniform Distribution with minValue = 1 and maxValue = 2 |
Activity "Receive and read E-Mail" |
Duration: Poisson Distribution with a mean value of 2 |
Messageflow "E-Mail" |
This element does not contain any simulation information in this model. |