Configuring ASM Tasks

How to configure ASM tasks for simulation

The following tabs are available on the behaviour pane of the task properties dialog. The simulation logic visits each of these configuration panes, in turn, to determine how the task will behave (with the exception of the variables pane, which will be discussed further below):

Pre-conditions - are evaluated to see if the required information is available for the task to be attempted, and whether any other user-specified conditions are met. If this succeeds then:

Resources (and prioritisation) - is evaluated to see if all required resources are available (ie not currently in use by other tasks), and whether the task is of higher priority than all other tasks which meet their pre-conditions and which require one or more of the same resources. If this succeeds then:

Pre-process - ing is undertaken to update any user-specified simulation variables according to user-specified functions, possibly written in terms of other simulation variables and possibly including a stochastic component. Then: 

Duration - is determined, either as a user-specified value (eg. 5 days), by selecting from a user-specified probability density function (eg. between 3 and 5 days), or by evaluating a user-specified function which may reference one or more simulation variables. The specified duration then elapses (other simulation events may happen in the meantime; this task may be interrupted if upstream information is updated while it is in progress). Then:

Outcome - if the task can have one or more output scenarios (ie if it is an iteration construct or a compound task), one of the outputs is chosen - either stochastically or according to user-specified logic which may reference the simulation variables; then:

Post-process - ing is undertaken to update any user-specified simulation variables according to user-specified functions, possibly written in terms of other simulation variables and possibly including a stochastic component. This includes updating the state of information flows, as described above.

By configuring these options for the tasks in a simulation model, it is possible to completely specify how the simulation model will behave. The default values on most tabs will be sufficient for getting started and for most simpler models. The Preconditions and Duration tabs are usually the most important to consider, to ensure that the task starts under the desired conditions and finishes after the desired time.

See also: Simulation variables in the ASM toolbox