Scheduling Warning Messages

Dependencies

Soft dependencies don’t have a scheduling impact.

A strong dependency ensures that the starting point of a dependency is before the target point of a dependency.

Strong dependencies (solid line on a Gantt chart) connect tasks in the following ways:

  • end to start

  • end to end

  • start to end

  • start to start

There are two types of strong dependencies:

  • ASAP - one task immediately follows the other

  • non-ASAP - one task follows the other, but doesn’t have to follow immediately

Lag time:

  • a mandatory gap between tasks

Unable to change dates

The dates of this task are determined by the dependency linking it to another task.

The dates of this task are determined by the dependencies linking it to other tasks.

A strong dependency makes it impossible to change the task dates in a way that would break the rules:

  • Task can’t be moved on the Gantt module timeline

  • Task can’t be moved in the Resources module

  • Task dates can’t be manually changed (editing a date in a board column, Gantt module column, task details pop-up)

To see the dependencies, go to the Gantt module.

  • You can use the search function to locate the task.

  • When you click on a task row, the row is highlighted in blue (the task is selected). When you clear the search, the task is still highlighted in blue.

  • When dependencies are collapsed, you can click on a dependency dot to see the details.

  • When dependencies are expanded, you can see dependencies visualized as arrows connecting tasks.

Solutions:

  • move the source task before moving the target task.

  • change the task scheduling mode to manual (automatic rules no longer apply - you can manually change the dependency dates). The dependency arrow is orange to indicate the rules are broken, but you are allowed to place the task wherever you want.

  • change the dependency type to ‘soft’ - soft dependencies don’t have a scheduling impact. They can be used to indicate a connection between tasks.

  • remove the dependency.

Dates adjusted by a dependency

Dependency rules have repositioned a task.

In the example below:

  • strong ASAP dependency connects tasks - an ASAP dependency positions source and target points right after the other. Lag time is added (when specified).

  • Scheduling mode of the target task was manual (dependency didn’t apply).

  • Scheduling mode of a task changed to auto bottom-up - dependency is applied. The task is moved.

When a target task doesn’t have start/end date, it is not on the timeline. Once a task is positioned on the timeline, dependency rules apply.

Period mode

Unable to change dates

When a task is in the ‘auto top-down’ scheduling mode, it adjusts its period to fit under the parent task.

Solutions:

  • Change the position of the parent

  • Change the period mode

    • of the child to ‘manual’ - automatic rules don’t apply. You can position tasks as you want.

    • of the child to ‘auto bottom-up’ - parent task period is modified by children

    • of a child to ‘auto basic’ - a task responds only to dependencies and non-working days. Period and position of the parent are ignored.

  • change how tasks are nested in the tree

When a task is in a ‘locked’ scheduling mode, its period cannot be changed (can’t be repositioned on a timeline, dates can’t be manually changed). A child in an ‘auto top-down' scheduling mode adjusts its period to fit under a parent.

Solutions:

  • Change the scheduling mode of the child task

  • Change the period of the parent task (if parent is ‘locked', the parent scheduling mode must be changed to allow for changes of its period).

  • change how tasks are nested in the tree.

 

A task has a start/end date - start/end cannot be modified (the task can’t be moved on a timeline and dates can’t be manually changed).

A task doesn’t have a start/end date - start/end date can’t be entered.

Solution:

  • change the task scheduling mode.

The period of an auto bottom-up task is based on the periods of its children.

When children don’t have a start/end date, the parent task doesn’t have dates.

Solution:

  • change the parent period mode

  • change the dates of the child tasks.

Dates adjusted by parent task

Parent task dates are changed. The child task adjusts its period to fit the parent.

The child didn’t have dates. Once the child is placed on a timeline, it adjusts to fit the parent.