Working with queuing network models

A queuing network model (QNM) estimates service performance against changes in business driver volumes or infrastructure configuration. It can predict:

  • Response time
  • Throughput
  • Queue length
  • Utilization

These metrics are either computed for a single resource or for a complex network; predicted values are then automatically compared with the service levels specified as thresholds on response time and utilization.

Related topics

Modeling-capacity-usage

Creating-a-model-workflow

The following table specifies the system resource types supported by QN models, including the corresponding metrics:

The model wizard will enforce these constraints by preventing you from selecting unsupported metrics.

For more information about how to work with E-QNM, see the following topics:

Example of the QN model type

The following figure shows an example of how an input-output table for a QN model appears in BMC Helix Capacity Optimization.

Example of an input-output table for the QN model
plot_QN1.png

The following table describes the Business Drivers (formerly known and shown in the figure as Workloads) and Systems in the example.

The following figure shows the response time chart for the example.

Response time plot before computer upgrade
plot_responsetime.png

Beyond the given threshold, the response time experiences an exponential increase in value (the region shaded red).

The current system can be improved, as shown in the following figure.

Upgrading the computers to see the effect on the response time
plot_QN22.png

Applying this change yields the plot shown in the following figure.

Response time plot after computer upgrade
plot_responsetime2.png

The response time drops compared to the earlier values.

With BMC Helix Capacity Optimization, you can simulate various scenarios to arrive at the solution that best corresponds to your needs.

 

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