Activities

Activities are the only BPMN entities that actively consume time. Therefore the activity’s duration is the most important simulation property.

Once you click the button next to the Duration label, you can select one of the stochastic distributions described in the Distributions topic with help of the Time Editor.

Several simulation properties will only be unlocked, if you add some optional Activity Properties. Currently there are three options, which are listed in the table below. By selecting one of these properties, an additional input box will appear in the Must-Have Simulation Properties area.

Simulation Properties of Activities

Activity Properties

Looping

Determines whether this activity is looping. This means it will be executed n times until a certain condition is being evaluated to true.

Multiple Instances: Parallel

Determines whether this activity is being executed in n parallel instances.

Multiple Instances: Sequential

Determines whether this activity is being executed n times in a row.

Must-Have Simulation Properties

Duration

The duration of the activity. You need to select one of the stochastic distributions and parametrize it as adequately as possible for your process.

Looping Condition

Defines the condition to break the loop. As long as the condition is evaluated to false, the activity will be started again.

  • When the expression’s result is true, the loop will break.

  • You can either write a simple mathematical term like x>5; (Language-Selection: F(x)). x must be defined somewhere else before) or you can formulate a complex Python script.

Number of Parallel Instances

This expression defines the number of parallel instances of the activity. The approach is similar to the Looping Condition. The sole difference is that you can simply put a number into this box, which indicates the number of parallel instances. Another example is x+1, though x must be defined or altered somewhere else.

Number of Iterations

This expression defines the number of iterations of the activity. The approach here matches with the Number of Parallel Instances.

Optional Simulation Properties

Expression

In this text box you can define custom attributes (e. g x=5), or operations that shall be executed in this activity (e. g. a Python-script).

Stochastic Attribute Assignment

In addition to Expression field, this option gives you the possibility to use one of our stochastic distributions to calculate the value of an attribute.

  • E. g. "x" gets its value from the Normal Distribution with the parameters:

    • Mean-Value = 4,

    • Standard-Deviation = 1

Participant

Assign participants to this pool or lane. See topic Organization Diagram for more information.

Inherit Resources

This Check-Box determines whether this activity shall inherit its superior elements' resource demands. E. g. the activity’s Pool demands n entities of resource x. If you check this property, the activity will also demand n entities of resource x. See Resources topic for more information on the resources concept.

Resource Priority

This property represents the priority of this activity in the resource allocation algorithm.

  • The higher the priority is set the faster this activity (or the process instance which is currently working off this activity) will be provided with the needed resources.

  • This option gives you the possibility to prioritize your activities in the resource allocation, because in reality there are often tasks that are more important than other tasks.

Incoming Token Mode

  • Default

  • Numeric

  • Dynamic

Incoming Token Count

Defines the number of tokens that must arrive before the activity is executed.

Incoming Token Count Variable

Defines the variable that determines the number of incoming tokens.

Outgoing Token Mode

  • Default

  • Numeric

  • Dynamic

Outgoing Token Count

Defines the number of outgoing tokens after the task is completed.

Outgoing Token Count Variable

Defines the variable that determines the number of outgoing tokens.

Report Properties

Generate Box-Plot

Gives you the option to generate a Box-Plot diagram for this activity.

  • These diagram types are very expensive in relation to the simulation time advancement.

  • The more Box-Plots you want to be generated the slower the calculation period of the simulation becomes.

Subprocess Activities

The subprocess activity also contains a property called Use Stochastic Duration. This is useful when you have not yet created the subprocess model (or did not specify any simulation specific data in that subprocess model) but still expect valid simulation results.

Subprocess Activity Properties

Use Stochastic Duration

Determines whether this subprocess activity shall use the Stochastic Duration, which can be assigned in its Duration property. By enabling this property, the underlying model to the subprocess activity will not be simulated. It will be ignored and the simulation replaces the execution of the model with a stochastic distribution, which then represents the time that is needed to execute the subprocess model.