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NEW: Gather and Disperse Modules


By Nancy Zupick, Consulting & Support Manager
Published: January 12, 2018

Categories: Consultant’s Corner, Customer Service, Manufacturing, Supply Chain/Logistics

In keeping with our continued effort to make modeling more intuitive, the new Gather and Disperse modules will make it far easier to seize and release groupings of resources.

These new modules allow for more realistic modeling of situations where multiple resources may be needed to complete a task more efficiently and where there is a range of capacity units available. For example, in the case of an airplane cleaning crew, the ideal staff size might be five individuals available to clean the cabin area and bathrooms in order to expedite the turnaround of the aircraft for the next flight. Having five people available to clean the plane will result in an ideal turnaround time. A smaller group could complete the task.  However, if the task is completed by a smaller cleaning crew, the time to complete the task increases as the cleaning crew capacity is reduced.

What makes Gather more powerful than a Seize module is that it can gather the necessary capacity units from across all resources in the specified set.  The Seize module allows you to seize from a Set, but you are limited to seizing the maximum of the resource with the greatest capacity in the set. Consider the following example:



Cleaning crew 1

3 people

Cleaning crew 2

4 people

Cleaning crew 3

5 people

Cleaning crew 4

6 people


Using a Seize module, the most units of capacity an entity will ever be able to seize is 6 units, because there is at least one resource that has a capacity of 6. If an entity tries to seize 7 or even 18 units (the total number of capacity units in the set), the entity will remain in queue forever.  In the past, you would have to design the model to accommodate situations like this, create decision logic to calculate the number of resources available in a set, or even go through multiple decision trees in order to seize the desired capacity.

Gather changes this. Gather is a very specialized seize that is able to seize resource capacity units across multiple resources in a set. So in the example above, you could seize all 18 units of capacity if they were available. Additionally, you can specify both a desired number of units to complete a task and a minimum number you are willing to accept. Below is a screen shot of the Gather dialog:

The Gather works specifically with Sets and uses the same selection rules as the Seize module. The Minimum Required Units allows the user to specify the minimum number of capacity units required to perform the task, which means that if that number of capacity units is not available the entity would not proceed logically. Maximum Desired Units is the total number of capacity units desired in order to perform the task. This value would typically be defined as the capacity units needed to reduce the amount of time necessary to complete a task. The Save Attribute feature allows the user to define an attribute to hold the total number of capacity units seized.

The Disperse Module allows the user to release those resources seized via the Gather. Below is the Disperse dialog box.

In the case of the Disperse, the user can choose to release all units seized or perhaps utilize several Disperse modules to progressively release units after specific logic is executed.

Gather and Disperse will be very helpful in designing logic to accommodate situations like emergencies that require a large number of resources regardless of skill set (disasters), military operations where cross sections of staff might be required, or as in the case noted earlier, those tasks that could be completed faster if more resources were available. I am personally looking forward to using these new features of Arena. 


The Author

Nancy Zupick

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