The Create Task Sequence activity will create an empty task sequence and dispatch it to a task executer. A task sequence is a series of actions (known as tasks) that can be assigned to a task executer (such as an Operator or Transporter).
Be aware that you don't have to use the Create Task Sequence activity at the beginning of every task sequence. Using any of the task sequence activities in a process flow will automatically create a task sequence any time that task sequence is used in a simulation run, which means the Create Task Sequence isn't technically necessary.
With that in mind, there are a few reasons why you might decide to use a Create Task Sequence activity:
When you use a Create Task Sequence activity, you are essentially grouping a set of tasks together into a single unit, so the task executer will not do anything else until that entire group of tasks is finished. Once the task executer has completed all of the tasks in a task sequence, the task sequence will be deleted.
The Create Task Sequence activity only allows one connector out. See Adding and Connecting Activities for more information.
The following image shows properties for the Create Task Sequence activity:
Each of these properties will be explained in the following sections.
Used to change the name of the activity. See Name for more information about this property.
The Font button opens a window to edit the activity's background color and font properties. See Font for more information about this property.
The Statistics button opens the activity's statistics window. See Statistics for more information about this property.
Use the Task Executer / Dispatcher box to select the task executer or dispatcher that you want to assign the task sequence to. If you want to create a task sequence but not dispatch it, click the button so that this box now reads None. If you want to dispatch the task sequence at a later time, you should click the remove button and use Dispatch TS (Task Sequence) activity to assign the task sequence to a task executer later in your process flow. See Dispatch Task Sequence for more information about this activity.
The Priority box sets the priority level of the task sequence. By default, task executers will complete task sequences and activities in the order they were received (first in, first out). However, you might want a task executer to complete more important tasks first. You can use the Priority box to cause the task executer to work on higher priority tasks sequences before lower priority task sequences.
By default, all task sequences are assigned a priority of 0, but you can enter in any number in the Priority box. By default, Task executers will prioritize task sequences to perform higher priority task sequences first through their Queue Strategy property. For example, imagine you create a task sequence with a priority number of 1 and another with a priority number of 2. If both task sequences are waiting in a task executer's queue to be performed next, the task executer will work on the task sequence with the priority number 2 first.
The Preemption menu sets the preemption value of the task sequence. Preemption is when a task executer stops its current task sequence to work on the preempting task sequence. You can use the Preemption menu to determine if and how preemption occurs.
For example, Operator A's most important responsibility is to repair machines. When there are no machines to repair, however, it should also transport material throughout the model. If a machine breaks down while Operator A is in the middle of transporting a flow item somewhere, then the Operator should stop whatever it is doing and repair the machine, instead of finishing the transport operation. To simulate this behavior in your model, you'll have to make sure that the Operator's machine repair task sequence is set to preempt the task sequence for transporting flow items.
The Preemption menu has the following options:
Assigns a reference on the specified label/node to the created task sequence. See the Assign To section of Common Properties for more information.