Reporting Utilization of Individual ResourcePool units

Question

In Anylogic, How can I get statistics such as utilization of individual resource pool units? As the resourcePool.utilization() function returns the mean utilization for all units in the resource pool. Is it possible to access the data of each resource pool unit? Any ideas? Thanks in advance!

Answer 1

Updated Answer

There is an easier way to get the utilization for individual resource units:

1. Define a custom resource agent type, as explained here
2. Set this new custom type for your resource pool as New resource unit
3. Add an empty population of this custom resource type (here named myResources)
4. In the resource pool under Advanced/Population set this empty population

Now you can access the individual resource pool units' utilization, with x as the index of the unit:

myResources(x).getUtilization()

In order to keep track of more complex statistics, you might still need to use the more complicated solution of the original answer.

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Original Answer:

You can build something yourself:

1. Use the On seize and On release code in the ressourcePool to notify your custom ressource Agent that it is active/not active. You can pass a message to the agent or call a function inside the agent.

2. The ressource agent can save its current state in a variable, statechart or similar.

3. You can then use the standard statistic module from the Analysis palette to aggregate the information, for example to get the individual agent's utilization.

Answer 2

[This answer is designed to explain more fully why Florian's answer works / is necessary and the wider context of the problem (really two problems) and solutions to it.]

There are two interwined issues here:

1. Creating resource unit agents that have per-unit utilization calculated and accessible.
2. Actually accessing individual resource units. (A ResourcePool does not have a get function or similar to directly get the agents inside it.)

This is not all explained very clearly in the AnyLogic help.

Creating Special Resource Unit Agents

Per-resource-unit utilization (as well as other functionality) is available as part of the special resource unit API (Application Programming Interface; basically a set of functions) discussed in the Library Reference Guides > Process Modeling Library > Resource functions help page.

However, this is only accessible if you create your own custom resource unit agent type; when you create a Resource Pool, by default the units therein are vanilla Agent objects and do not have this special resource unit functionality. (You can get the overall utilization of the pool via its getUtilization function.)

For the Process Modeling library, you can create a custom type which acts as a resource unit in three ways:

• New --> Agent Type (right-click menu for your model in the Projects palette), specifying Agent will be used in flowcharts as: Resource Unit;

• The Resource Type element in the Process Modeling Library palette. (This effectively shows the same wizard as the first method but with the use in flowcharts not present and automatically set under the covers.)

• Clicking create a custom type when adding a Resource Pool (under the New resource type setting), which takes you to the same wizard as the second alternative above.

[Java / Technical Note: What happens is that you create your own agent type (subclass of Agent in Java terminology) which implements the special AnyLogic-provided IResourceUnit interface (a Java thing which defines all the special resource unit API functions that are available). This is relevant later...]

Accessing Individual Resource Units

There are several ways to do this:

(1) In the actions of your Resource Pool you have access to the current resource unit via the special keyword unit. (Hover over the lightbulb when editing these action boxes to get info on this.) However, this just provides them as a vanilla Agent (even if it is actually a custom resource unit, let's say of type MyResourceAgent).

So you have to cast (a Java thing) unit to effectively say "I know this is actually a MyResourceAgent so let me see it as one of those please"; e.g.,

((MyResourceAgent) unit).getUtilization()

(2) As in the the Library Reference Guides > Process Modeling Library > Resource functions help page, you have access to all the resource units an agent has seized via that agent's built-in resourceUnits collection (list).

However, that again contains them just as Agents, so you have to cast them; e.g.,

((MyResourceAgent) agent.resourceUnits.get(0)).getUtilization()

(3) If you set your resource pool up so that its agents are added to a custom population (rather than the 'hidden' default population), you can then access them explicitly at all times via that population.

Following the earlier example, you create an empty population (let's say called myResourceUnits for agents of type MyResourceUnit) and set the Resource Pool to Add units to: Custom population (in its Advanced properties), selecting the population you've set up.

Then you can access individuals via, e.g., myResourceUnits(0).getUtilization().

NB: You have to be aware here of what you are doing depending on how you set the When capacity decreases setting in your Resource Pool. If you set it to Units are destroyed then your population will change size as the pool changes capacity (say via a schedule).

(Java / Technical Note: In all the cases above, you can also cast to IResourceUnit since that is the interface all custom resource agent types are implementing. But that won't give you access to any functionality you added to your custom resource type such as its own set of parameters.)