Concepts

Tasks

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Creating Scheduling Relationships for Tasks

This section explains how to create scheduling relationships between tasks on a work order. You can do this by entering the predecessor information for each task.

Note: When you create a work order with multiple tasks, the system automatically sets up finish to start dependencies between the tasks. If necessary, you can edit or delete these dependencies.

If the work order already has the “Planned” status, you will need to redraft the work order before you can add or edit dependencies.

Relationship Types

Four relationship types are available:

Relationship Type	Description	Example
Finish-to-start (FS)	The successor task cannot start until the predecessor is finished. This is the default relationship type for tasks on a work order.
Start-to-start (SS)	The successor task cannot start until the predecessor starts.
Finish-to-finish (FF)	The successor task finishes at the same time as the predecessor.
Start-to-finish (SF)	The successor task finishes at the same time as the predecessor starts.

Lags and Overlaps

For each task relationship, you can enter a lag time. You can use lags to offset the start or completion date of two linked tasks. For example, if two tasks have a finish-to-start relationship with a four-hour lag, task B will start four hours after the completion time of task A.

You can also use lag time to overlap two tasks by entering a negative lag time. For example, to set task B to start four hours before task A is completed, link the tasks with a finish-to-start relationship, and enter a lag of “-4” hours.

Note: Task scheduling relationships (predecessors and successors) do not apply when simple scheduling is used.

To Enter Predecessors for a Task

1.	Open the work order task. On the Planning view, select the Planning tab and the Dependencies tab. This tab shows the existing dependencies for this task.

2.	Make sure that editing is enabled.

3.	Click New, or double-click an existing dependency. The Predecessor Details dialog appears.

4.	Enter the predecessor information on the General tab:

Setting Name

Description

Work order

The work order that owns the predecessor task. By default, the system enters the work order that owns the current task. You can select any open work order at the same site. To select another work order click Browse.

Task

Select the task that is the predecessor to this task. For example, if you are creating a relationship from task 3 (successor) to task 2 (predecessor), select task 2 in the list. You can select any task that: • Is open • Is owned by the selected work order You cannot select a task that is already dependent on the current task, or that would create a relationship that would result in a circular dependency. For example, if task 2 is dependent on task 1, and task 3 dependent on task 2, you cannot make task 1 dependent on task 3.

Type

Select the type of predecessor relationship: • Finish-to-start (FS): The successor task cannot start until the predecessor is finished • Start-to-start (SS): The successor task cannot start until the predecessor starts • Finish-to-finish (FF): The successor task finishes at the same time as the predecessor • Start-to-finish (SF): The successor task finishes at the same time as the predecessor starts

Lag

Enter any required lag time for the relationship. You can use lags to offset the start or completion time of two linked tasks. For example, if two tasks have a finish-to-start relationship with a four-hour lag, task B will start four hours after the completion time of task A. To overlap tasks, enter a negative lag time. Using the same example, entering “-2” hours sets task two to start 2 hours before the completion time of task one.

5.	Select the Details tab. On this tab, you can enter any notes about the relationship and review the descendants information.

6.	To save the relationship, click OK.

7.	To add more relationships, repeat steps 3 to 6.

8.	When you are finished, save the work order task.