Sequencing mechanism
You can use sequence numbers to define the order in which tasks or task groups are executed. This sequencing mechanism saves users time, by eliminating the need to manually define the flow between tasks or task groups.
For example, change request users can add three tasks from the list in a task template, and then specify the order in which they execute (1, 2, and 3). This is equivalent to configuring a successor and predecessor model as Start'Task1'Task2'Task3.
The sequence for each task or task group entered by users is converted to a flow definition in TMS. In the preceding example, when three tasks are ordered as 1, 2, 3, three flows are created automatically as follows:
Flow#1 : Start ' Task1
Flow#2: Task1 ' Task2
Flow#3. Task2 ' Task 3
The sequencing mechanism has the following fixed settings on the flow object that cannot be changed:
- Evaluate if Predecessor Failure? "No"
- Evaluate if Predecessor Canceled? "Yes"
- Flow to Successor when "All Complete"
With these settings, all tasks and task groups in the same sequence must be completed before the tasks or task groups in the next sequence level can begin. For example, in the following table, Task 4, 5, and 6 (at Sequence level 2) are activated only if Task 1 (at Sequence level 1) and Task 2 (at Sequence level 1) is completed.
Sequence level | Task |
|---|---|
Sequence 1 | Task 1, Task 2 |
Sequence 2 | Task 4, Task 5, Task 6 |
Sequence 3 | Task 7, Task 8, Task 9 |
When a task or task group is added, the default sequence is the next available sequence level. For example, in the following table, if a Task 10 is added to the list of existing tasks, it would be set at sequence level 4.
Sequence level | Task |
|---|---|
Sequence 1 | Task 1, Task 2 |
Sequence 2 | Task 4, Task 5, Task 6 |
Sequence 3 | Task 7, Task 8, Task 9 |
Sequence 4 | Task 10 |
After a task is added, you can change the ordering using the sequence number. Increasing the sequence number moves the task down the list. Decreasing the sequence number moves the task up the list.
During runtime, the following rules ensure the integrity of the process flow:
- The sequence cannot move to a prior sequence level that is completed.
- The sequence level cannot be changed on an active or completed task.
You can change the sequence number using the up and down buttons on the user interface, or by setting the sequence number directly in the corresponding column on the table field.
During the Definition stage, sequence and dependency information is stored in the Flow template. During the Execution stage, the association information is stored in a separate Flow table. The following figure illustrates the sequencing model.
Sequencing model