Setting Queue Management

The Queue Management parameters enable you to assign a priority and a maximum desired length to each queue in the group and also to apply an optional Queue Closing Scheme.

The priority and length settings principally control when new queues open but are also used to adjudge when queues should close if a closing scheme is running.

The closing scheme itself instructs the software when to close queues that are no longer needed and how to distribute any Entities that may still be queuing when the decision to close a queue is taken.

Priority and desired length

Setting the ‘Priority’ and ‘Maximum desired queue length’ enables you to set the point at which queues fill up and alternative queues need to open to cope with demand.

Consider the case of a Queue Group containing three Queues with the following attributes.

Name	Priority	Maximum desired length
Queue #001	1	10
Queue #002	3	10
Queue #003	2	8

Entities will initially head to Queue #001 as it has the highest priority (1). Once this queue has 10 people waiting in it, Queue #003 will open as it has the next highest priority (2).

Entities will begin to choose between Queue #001 and Queue #003 in accordance with the Entity Choice Assessment Method associated with the Queue Group (i.e. shortest queue or shortest distance to the queue).

If Queue #003 reaches its capacity of 8 people while Queue #001 is also at capacity, then Queue #002 will open and Entities will start to join it as well.

Queue Closing

The Queue Closing scheme uses the priority settings to decide which Queues to close first: lowest priority Queues are closed before those with a higher priority.

The scheme also uses a ‘threshold’ setting, which you can set at anywhere between 0 and 100%. This threshold indicates an amount of available queue capacity above which the lowest priority Queue will close. Capacity is calculated using those Entities already waiting in Queues and those Entities already on their way to join Queues.

So, in the example above, if all three Queues are open and the threshold is set to 50%, then the lowest priority Queue will close when the remaining capacity in the other two Queues is greater than 50% (in this case a capacity of more than nine Entities).

Note: When a Queue closes, you can decide whether Entities waiting in that Queue remain there until they receive the service they are queueing for (no other Entities can join the Queues once it has closed, however) or you can send these Entities to the other open Queues.

In the latter case, capacity is calculated by also counting these Entities that will need to be reallocated.

To set Queue Management parameters:

Check the box labelled ‘Use queue management’.
For each Queue:
- Double-click in the ‘Priority’ column and set a priority (1,2,3, etc.)
- Double click in the ‘Maximum desired queue length’ column and enter the maximum number of Entities you would like the Queue to contain.
The third column, ‘Close at’, displays the threshold figure at which a Queue will close (if it is 15 it means that when the number of Entities queuing in all Queues is 15 or fewer, then this Queue will close). This figure changes as you change the ‘Threshold’ setting (see step 4).
To apply an optional Queue Closing Scheme, check the box labelled ‘Use queue closing scheme’.
Set the ‘Threshold’ by sliding the horizontal bar or entering a percentage in its adjacent field.
If you want to send Entities in closed Queues to join other available Queues, check the box labelled ‘Redirect entities to remaining queues’. Otherwise, the Entities will remain until they reach the Queue’s Delay Point and move on.
Click OK to save your settings.

Setting Queue Group links

The ‘Links’ tab enables you to specify whether Entities will join one of the Queues according to ‘Shortest queue’ or ‘Shortest distance’. See Linking methods for full details on Queue Group linking.

Queue Groups and Delay Points

There’s no need to link Queue Groups to Delay Points: the individual Queues within the group take care of that. The point of the Queue Group is to enable Entities to choose between the available Queues within the group.