WebSphere Lombardi Edition 7.2 > Simulating and optimizing processes


Sample simulations


Run a quick simulation

Before you actually implement a process, simulations can help you pinpoint potential issues such as bottlenecks caused by resource constraints or a particular path being taken more often than is optimal. In this sample, we'll walk through setting simulation values for the elements in a process and then quickly running a single simulation of the process.

The following image shows the diagram of the sample process that we'll be simulating. The process is used to determine whether to reject or accept a billing dispute. The flow of the process is as follows:

To start, let's set simulation values:

  1. Select the Approval Required gateway in the diagram and then select the Simulation option in the properties.
  2. To facilitate running a quick simulation, we leave the Selected scenario at Default and then estimate that the Outgoing Flow Percentage for the Yes (Review for Approval) path is 60 per cent. This means we believe that 60 per cent of the disputes that don't require research are going to require approval as shown in the following example.

  3. Select the Review for Approval activity in the diagram.

    In the Simulation properties, we want to use the Default scenario for this quick simulation so we leave that setting and then estimate the Execution Time. We select Normal for the distribution type and we think it will take managers an average of 1 hour and 10 minutes to approve or reject a dispute.

  4. To estimate the number of managers for our simulation, we click the Manager swimlane. Click the default participant group for the lane (Call Center Managers) to open and edit the Simulation properties for the group.

    We expect to have at least two managers available to handle this work and so under Simulation Properties, select Use Estimated Capacity and enter 2 in the corresponding text box.

  5. To run a simulation using the values provided in the preceding steps, go to the BPD diagram and select the icon illustrated in the following image to start a new simulation for the current process.

  6. When you run a simulation for your current process using the toolbar icon, the default Visualization mode is Wait Time. So, the heat map results highlight tasks that could potentially cause gaps in process execution because a person or system is not available to complete those tasks:

    The preceding heat map shows that the Review for Approval activity has the longest wait time of approximately 9 hours.

  7. To improve the Wait Time, we go back to the properties for the Call Center Managers participant group and change the estimated capacity from 2 to 4 managers.
  8. We run the simulation again from the toolbar, and this time the results are better:

    By doubling the available resources, we've reduced the wait time for the Review for Approval activity from 9 hours to 2 hours.

The Optimizer enables you to quickly manipulate simulation settings to ensure that you are able to closely represent the environment in which your process will run. In some cases, it may be necessary to alter the process design to accommodate other constraints. For example, in the preceding sample you may know that it is impossible to increase the number of available managers for this process. So, you might consider adding a Timer Event to the Review for Approval activity to remind managers of pending approvals at defined intervals. This would make sense if the pending approvals for billing disputes are higher priority than other tasks for members of this management group.

The advantage of the Optimizer is that you can create and save several Simulation Profiles to represent different staffing levels and other variables, which enables you to demonstrate predicted performance to your management or other corporate teams invested in the success of the process models. The following section illustrates the flexibility provided by Simulation Profiles and Simulation Scenarios when you need to analyze predicted performance to foster decisions about proposed process designs.


Taking advantage of simulation profiles and scenarios

After running some quick simulations in the preceding section, we know that adding resources to our process results in acceptable wait times. But, we don't believe it will be possible to actually increase resources for the problematic activities. We could, however, devise a way to categorize billing disputes so that a smaller percentage of disputes would actually require approval. Because we want to demonstrate the options and outcomes to the corporate automation team, we decide to create two separate Simulation Profiles for this single process:

To create the simulation profile called Current Flow, follow these steps:

  1. Open the Billing Disputes process in the Designer in Lombardi Authoring Environment.
  2. Select the Approval Required gateway in the diagram.
  3. Click the Simulation option In the properties.
  4. Under Simulation Profile, click the New button to create a new profile to represent the current flow of disputes that require approval.
  5. Name the new profile Current Flow and click OK.
  6. In the Outgoing Flow Percentage area, enter 60 for the Yes (Review for Approval) flow:

  7. Select each activity and gateway for which you want to specify simulation values for the Current Flow profile.

    When specifying Simulation properties for each process element, be sure that the Current Flow profile is selected.

To create the simulation profile called Improved Flow, follow these steps:

  1. Select the Approval Required gateway in the Billing Disputes process diagram.
  2. Click the Simulation option in the properties.
  3. Under Simulation Profile, click the New button to create a new profile to represent the improved flow of disputes.
  4. Name the new profile Improved Flow and click OK.
  5. In the Outgoing Flow Percentage area, enter 30 for the Yes (Review for Approval) flow:

  6. Select each activity and gateway for which you want to specify simulation values for the Improved Flow profile.

    When specifying values in the Simulation properties for each process element, be sure that the Improved Flow profile is selected.

We also need to create two separate simulation scenarios so that we can run a comparative analysis.

To create the first scenario, follow these steps:

  1. In the Designer in Lombardi Authoring Environment, click the plus sign next to Processes and select Simulation Analysis Scenario from the list of components.
  2. Name the scenario Bill Disputes Current Flow and click Finish.
  3. Click the Limit process instances radio button and set the Max instances field to a value of 50.
  4. Under Process Apps to Include in Analysis click the Add button and then select the process application that contains the Billing Disputes process.
  5. Under Processes to Include in Analysis click the Add button and then select the Billing Disputes process from the list.
  6. Click Default under Simulation Profile to display a list of Simulation Profiles that have been created for the Billing Disputes process and then select the Current Flow profile.
  7. Leave the Participant Group Overrides section blank.

    The following image shows the completed scenario:

  8. Click Save icon in the main toolbar.

To create the second scenario, follow these steps:

  1. Click the plus sign next to Processes and select Simulation Analysis Scenario from the list of components.
  2. Name the scenario Bill Disputes Improved Flow and click Finish.
  3. Mimic the settings from the previous scenario, except this time, choose the Improved Flow Simulation Profile.
  4. Click Save in the main toolbar.

Now we can run in Simulation versus Simulation mode to compare wait time, execution time, and so on.

  1. If you haven't already done so, open the Optimizer using the drop-down list at the top of Lombardi Authoring Environment.
  2. In the Analysis Scenarios view, choose Simulation vs. Simulation from the Mode drop-down list.
  3. Under Selected Scenarios, for sample A click the Select button and choose Bill Disputes Improved Flow from the list.
  4. For baseline B, click the Select button and choose Bill Disputes Current Flow from the list.
  5. In the Heatmap Settings view, we want the Visualization mode setting to be Wait Time with the specific settings shown in the following image:

  6. Click the Calculate button in the Analysis Scenarios view.

    The heat map shows that reducing the percentage of disputes that require approval decreases the wait time for the Review for Approval activity from approximately 9.5 hours to 2.5 hours.

So, we are able to demonstrate that reducing the percentage of disputes routed for review to 30% (we theorize that we can do this by adding a task and business variables to categorize disputes), improves wait times and process execution in general. The Optimizer enables you to quickly demonstrate the performance issues, plus Lombardi enables you to quickly build and then demonstrate proposed design solutions.

Parent topic: Simulating and optimizing processes

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