Viewing a Simulation

This procedure describes how to run a simulation. This procedure describes the basics of using the various pop-up toolbars that appear with both the Process Simulation and Resource Simulation commands.  For an description of how Resource Simulation differs from Process Simulation , see About Resource Simulation.
You can also use process simulation to improve performance as you add simulation activities.
This procedure assumes that you have a process with activities or loaded or a resources with activities assigned to them.
  1. Do you want to see data readout windows while the simulation is running?

    • If YES, see Using Data Readout -- attempting to use the data readout command during a simulation makes the simulation stop.  It can be resumed after opening the data readout windows.
    • If NO, go to the next step.
  2. Select the process, activity, or task on the PPR tree.

    • If you select an activity instead of a process, only the activity is simulated in the context of the process, but the whole process is not simulated.
    • If you select nothing, the entire process is selected by default.
    • If a resource is assigned to an activity, and the resource has a task or tasks assigned to it, see Simulating Processes with Tasks Assigned to Resources to be sure you see the operations assigned to the tasks.  You can also view the task alone by selecting the task in the PPR tree.
  3. Click Process Simulation on the Simulation toolbar.

    The icon turns orange.  The Process Simulation and Simulation Control Tools pop-up toolbars appear.
    The table below provides the meaning of each of the VCR-like buttons.

    Jump to start


    Step forward (by default, shows simulation one tenth of a second at a time). 
    To alter the number of seconds or other time units, use the spinner that controls speed.  To alter the time units, see Tools > Options > General > Parameters and Measures > Units.

    Run (shows simulation as continuous motion, a.k.a. Play)

    Jump to end


    Simulation mode: Single/Continuous

    The simulation mode determines whether the simulation is shown once or continuously;  pressing this button toggles between the two modes.

    The image to the left shows the default simulation mode: Single, that is, to show the simulation once.

    The image to the left shows the Continuous simulation mode button.

    Step size

    To increase or decrease the speed of the simulation, use the spinners.

    Simulation time:  This field tracks the time within a simulation when actions occur.

    In addition, users may input a value in the time editor field. The simulation engine will attempt to "jump" to the given time. If the input value is outside the simulation start-end boundary, the following actions will be taken:

    • If the input value is greater than the end time, the simulation will stop when reaching the end and a message will be displayed to the user.
    • If the input value is smaller than the start time, the simulation will stop when reaching the start and a message will be displayed to the user.
    The use of the commands in the Simulation Controls pop-up toolbar is explained in the procedures following this one. A complete list of these procedures is available here.
  4. Select the button(s) from the table above that provide you with the features of your simulation that you want to see.

    Animation occurs in the 3D view.

    A number of commands can be run while you run Process Simulation .  These shared commands include simulation commands such as Analysis Configuration and view commands such as Zoom In .  When you click on other commands (e.g., Zoom In ), the simulation pauses.  Once the command has finished, you can start a paused simulation from the pause point, click Run.

    When you use the Zoom In command icon or menu option, you are using a shared command.  Using the mouse to zoom in is not the same as using the Zoom In command in this context.
  5. End the simulation using one of the methods below:

    • Press the X (close) button in the upper right hand corner of the Process Simulation pop-up toolbar OR
    • Click Process Simulation (the icon changes from orange to its original colors).
If activities have precedence constraints, the precedence constraints are visible in the simulation.
  For more information about precedence constraints, see DPM Process and Resource Definition User's Guide: Basic Tasks: Changing Activity Properties: Precedence Constraints Management.
If a process contains a switch activity, the simulation reflects the output of the switch activity.
  If you have multiple windows open, the viewpoint appears in only the first window while you run Process Simulation , Process Verification , or Automatic Synchronization .
  Process Simulation recognizes Start/Start and End/End relations: that is, time constraints that enable activities to start or end at the same time.  Users should be aware of the following rules regarding these relations:
  • Start/Start and End/End relations cannot be enforced during simulation if the process contains simulation activities that have the calculated cycle time different from the specified cycle time.
  • Any Start/Start or End/End relations that force the activities to start at negative times are ignored, and a warning message is displayed.