Model 14 - Resources for Pools and Lanes

Goals of this lesson

  • Learn how to assign resources to pools and lanes

    • and by that assign them automatically to each activity, that lies in the pool or lane

Often we need to model divisions of companies. These divisions mostly use the same participant(s) throughout a pool or lane.

Therefore in IYOPRO resources can not only be assigned to activities, but also to pools and lanes. Model 14 consists of two pools, with the upper pool using the developer as participant. That means, every activity in this pool needs a developer resource. You will notice that the Simulation Properties of the Develop External activity has the option Inherit Resources, that is checked by default. If you do not want an activity in a pool to inherit the resources from the pool, you can deactivate this option.

How-to

14
Figure 1. Model 14 - Resources for Pools and Lanes

Approach

  • Select the top pool

  • Assign it the participant Programmer (just like you learned it in the previous lesson)

    • Under the Optional Simulation Properties of a User Task you will find the property Inherit Resources

    • This option tells the simulation, whether the specific activity in this pool shall inherit its resource needs

    • (It is activated by default. Just uncheck it, if you do not want the activity to inherit its pool’s or lane’s resource needs)

  • Select the bottom pool

  • Assign a participant called Project Manager to the pool

  • Now select the top lane (Realization) of the pool

  • And assign it a participant called Programmer

Explanation

What we did was to assign a programmer to the top pool. Since the activity "Develop (external)" has its Inherit Resources option activated, it will always need one programmer to fulfill its duty.

In the bottom pool we assigned a Project Manager, which will be required by both activities. Then we also assigned a Programmer to the top lane. This means that the activity "Develop (internal)" will need one Project Manager and one Programmer to be completed.

Report

See below for the run configuration, which we set up to receive the report statistics from below.

Please refer to the section Experiment Results for more information on the report specific data.

Run configuration

  • Stochastic Seed: 12345

  • Simulation start date: 1/1/2014 12:00:00 a.m.

  • Simulation stop time: 240

  • Simulation stop time unit: Hours

Report statistics

  • Figure 2 shows us that both developers have been in use (almost) throughout the whole simulation. (The 3 hours of idle time result from the specifics of the start events' inter-arrival times).

  • In contrary, the Project Manager has been in use for only 55 hours and was waiting for one of the Developers for 184 hours. Remember that the activity Develop (internal) requires one Project Manager and one Developer.

Model 14 resources
Figure 2. Resource statistics for Developer and Project Manager

  • Let’s take a look at Figure 3, which shows the utilization of the Developer role

  • We learn that the pool External Developers has been acquiring both developers' working time for 94.30 % throughout the simulation. The Pool Software-Company got only 5.7 % of their working time.

Model 14 Utilization Developer
Figure 3. Utilization of the Developer role

  • Figure 4 depicts the queue statistics for the processes waiting for either one of the Developers or the Project Manager

  • Due to the fact, that the Project Manager is being held up at activity Develop (internal), all the process instances arriving at activity Planning Workload must wait disproportionately high.

Model 14 queues
Figure 4. Queue-Statistics for the Developer and Project Manager

  • From Figure 5 (Activity Runtimes) we learn that this is exactly the case

    • The Project Manager finished the activity Plan Workload (executed 28 times [Obs]).

    • But the activity Develop(internal) has been executed only 27 times.

    • So the Project Manager is currently held at Develop(internal)

    • See this chapter’s subpage Prioritization of Resources for more information on this matter

Model 14 activity runtimes
Figure 5. Activity Runtimes

Explore

  • Try to explore Model 14’s dynamics by adding an additional Developer to the Organization Diagram.

    • On first thought, this measure should decrease the Project Manager’s waiting time for a Developer and consequently the waiting processes in the queues and the processes' lead times.

    • Right? Try it! You will be surprised! Please try to understand on yourself, what happens there by adding another Developer.

    • You can, add another Project Manager to improve your understanding of the model’s dynamics.