State Chart Timing

State Charts allow work items to be controlled through their behaviour rather than their physical position in the simulation. Using this feature you can control an Activity’s operation time based on how long it takes for a work item to be in, or to not be in, a particular state.

Timing Orientation

Select the Activity and choose Timing from the ribbon. In the dialog shown below, select ‘Until work item is in State’ and chose the Start Point of your chosen sub process from the dropdown list. The operation time for the Activity will now be based on how long the work item takes to progress to the end of the sub process.

State Chart Timing selected

If you wish the operation time to be calculated up until a work item leaves a particular state, then tick the ‘Not’ checkbox.

An example of State Chart Timing

The simulation below shows an admission process into a hospital and uses State Charts to control the condition progression of the patient. For more information on how to use State Charts in your simulation see State Charts .

State chart example simulation

The time spent in the hospital bed is dependent on how long a patient takes to transfer to the healed state. A patient has a % likelihood to progress or recover to each of the four states over time.

  1. Healed
  2. Condition
  3. Complex Condition
  4. Severe Condition

At the Activity named ‘Bed’ the timing orientation has been set to ‘Until Work item is in State: Healed’. This will ensure that a patient will not leave the bed until they have reached the healed state.

On running the simulation, patients transfer between each state based on the % likelihood, when they reach the healed state the patient will leave the bed and therefore reach the end of the simulation process.

State chart results example

In the above image there are currently 18 patients in beds, 6 of these have a complex condition, 9 have a severe condition and 3 are general. There are 234 patients in the healed state which is also reflected in the End Point throughput.