The Gantt Chart
Definition
The Gantt chart is a visual tool that helps project managers create and monitor their project schedules.
- It is used to define tasks, assign resources, organize tasks in a sequence and monitor progress.
- It enables you to include milestones, i.e. reference points, and parent tasks, i.e. extended periods with no resources assigned that contain groups of subtasks.
EndDefinition
Each task:
- Is defined using a Properties Inspector.
- Is identified in a unique way in the WBS (Work Breakdown Structure).
- Is assigned to a resource by defining users as participants in the project.
- Is initialized with a duration (workload) and a scheduled completion time which can be adjusted based on the progress reported weekly by participants in their time sheets.
- Has a financial cost.
Examples
Scheduled time vs Time spent on a task
The ABC software deployment project comprises a Documentation task.
- Scheduled completion time: 2 weeks from Sep 25 to Oct 6
- Duration of a working day: 7 hours
- Scheduled duration (workload): 6 days = 42 hours
==> Time sheet entered by participants assigned to the task:
Week 1 | Week 2 | Total | |
---|---|---|---|
Time spent | 2.5 days = 17 hours 30 min | 4 days= 28 hours | 45 hours 30 min |
Progress | 25% | 100% |
==> Summary:
- Overrun in terms of workload: 3 hours 30 min (45 hours 30 min spent - 42 hours scheduled)
- No overrun in terms of deadline as the task was completed on Oct 6
Parent tasks
Six level 1 tasks | ||
---|---|---|
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Create parent tasks | Procedure | Result |
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1. Select the Documentation task and click ![]() |
The Documentation task will become a subtask of the Documentation and training task and its number will be 8.1. |
2. Select the Production of training manual task and double-click ![]() |
The Production of training manual task will become a subtask of the Documentation task and its number will be 8.1.1. | |
3. Select the Training task and click ![]() |
The Training task will become a subtask of the Documentation and training task and its number will be 8.2. | |
4. Select the User training task and double-click ![]() |
The User training task will become a subtask of the Training task and its number will be 8.2.1. | |
5. Select the Administrator training task and double-click ![]() |
The Administrator training task will become a subtask of the Training task and its number will be 8.2.2. |
Notes
- Only project managers can modify the Gantt chart. Users who are defined as project participants can only access it in read mode.
- Tasks:
- Must be scheduled over a minimum duration of one day.
- Are late (displayed in red in the chart) if their scheduled end date:
- Is later than the project end date.
- Is earlier than the current date and if they are not completed by this date.
- Can be moved to another period as long as they have not started.
- Can have a modified duration as long as they are not completed.
- Can be deleted as long as they are not assigned to a resource.
- Parent tasks:
- Have a start date based on the start date of their first task and an end date based on the end date of their last task.
- Have an automatically non-modifiable null duration with no resource assigned.
- Become ordinary level 1 tasks when there are no subtasks.
- Workload (or duration):
- Is expressed in hours:minutes.
- Is always calculated in hours based on the working day duration defined for the project in the Duration of a Working Day (Hours) field in the Project form.
- Resources can be assigned for a given period:
- To one or more tasks for one or more projects.
- To actions for incidents or requests.
- Tasks and actions can overlap or be scheduled on the same day.
- No resource can be assigned to a milestone or to a parent task.
- The WBS is automatically updated each time tasks are reorganized.
Caution
- The WBS does not support more than 999 tasks by hierarchy level. If the number of tasks is more important for a level, you must divide your project into several sub-projects or you must create parent tasks.
- Non-working periods are not taken into consideration in the chart. You must exclude them manually.
- The hourly cost of the task is automatically initialized based on the hourly cost of the participant. If you want to enter another value, you should do so once you have assigned the resource.
- Once you delete participants, they will become inactive. You will no longer be able to assign tasks to them. Note: Previously assigned tasks will not be deleted and can be viewed in the resource-planning schedule.
- When you delete a parent task, all of its subtasks will also be deleted.
- You cannot move a task that has already started to another period, but you can modify its scheduled duration as long as it is not completed.
Best Practice
- When a project is created, you should start by creating the first and last tasks. The entire task schedule will then be displayed in the window and the most appropriate zoom level will be applied. You can then create the other project tasks.
- When you create a task, you can:
- Move it horizontally in the chart to define its start date.
- Resize it horizontally to define its end date and duration.
- Move it vertically to assign it to a resource.
- Click to display a quick view of the resources available. A vertical pane will show the scheduled period in the resource-planning schedule. Tasks that have already been assigned during this period appear in this vertical pane. This generally indicates that their participants are unavailable.
- To modify the duration of a parent task, you can move its subtasks to another period. Its period will automatically be updated based on the start date of the first subtask and the end date of its last subtask.
- Click
to refresh the chart if your modifications do not appear.
Menu access
Go to the list of projects > next to the project you want
Description of the Gantt chart
The screen is divided into five zones:
- The toolbar (1), used to perform actions on tasks and resources.
- The chronological list of tasks (2) (Note: The active task is highlighted in blue).
- The visual display of the schedule (3).
- The list of active participants and the resource-planning schedule (4) (Note: The active resource is highlighted in blue).
- The Properties Inspector (5) used to define the properties of the selected task.
Toolbar
: Used to add a new task to the task schedule. Click to open the Properties Inspector.
- If a task is selected in the list:
- The new task will be placed below it.
- Its start and end dates will be identical to the selected task.
- Its duration will be identical to the selected task.
- If no task is selected:
- The new task will be placed at the bottom of the list.
- Its duration will be equal to one working day.
- Its start date will be the current date.
: Used to add a new milestone to the chart in order to define a reference point during the project life cycle. Click to open the Properties Inspector.
example End of development
- The duration of a milestone is automatically null and non-modifiable.
- No resource can be assigned to it.
- If a task is selected in the list, the new milestone will be placed below it. Otherwise, it will be placed at the bottom of the list.
: Used to add a new participant to the list of active project participants. Assign the tasks you want to the participant.
- The participant will appear in the Resource list and in the Participants tab of the Project form.
: Used to delete the selected participant from the list of active project participants. You will no longer be able to assign tasks to deleted participants.
- The participant will be grayed out in the Resource list and will disappear from the Participants tab of the Project form. Click
to reactivate deleted participants in the list of active participants.
- Previously assigned tasks are kept and can be viewed when you click
.
: Used to delete the task or milestone.
- Only non-assigned tasks can be deleted.
: Used to convert the selected task to a parent task or subtask.
See the example.
example The Training task comprises the Production of training manual, User training and Administrator training subtasks.
moves the task to a lower hierarchy level.
moves the task to a higher hierarchy level.
- Each time a task is moved to a higher or lower hierarchy level:
- The WBS will automatically be renumbered.
- Scheduled periods will remain unchanged.
: Used to move the selected task up or down.
- Each time a task is moved:
- All subtasks are moved.
- The WBS will automatically be renumbered.
- Scheduled periods will remain unchanged.
: Used to save the chart.
: Used to modify the zoom level of the schedule.
- The timescale will automatically adapt to the zoom level and change to display years, months, weeks or days.
You can also browse through the chart using the horizontal scroll bar or by clicking the column headers of the two timescales.
(Note: Default display mode when the chart is opened): Used to adapt the zoom level automatically to display all project tasks from the start date of the first task until the end date of the last task.
Chronological list of tasks
WBS (Work Breakdown Structure): Unique ID automatically attributed to the task, indicating the hierarchy levels of tasks in the project.
- Tasks are numbered sequentially: 1, 2, 3, etc.
- Subtasks have the same ID as their parent task followed by a numeral suffix representing the hierarchy level that starts with 1.
example
- Parent task 5 --> Subtasks 5.1, 5.2, 5.3: Hierarchy level 2
- Parent task 3.2 --> Subtasks 3.2.1, 3.2.2: Hierarchy level 3
- WBS are automatically updated each time the order of tasks is modified and each time parent tasks or subtasks are created.
If numbering has become inconsistent, you should open the Project form and run the Recalculate WBS of Tasks wizard. All tasks will be renumbered and their hierarchy level will become 1. Caution: There will no longer be any parent tasks or subtasks.
Task Name: Name of the task.
- The left indent of task names is automatically increased or decreased to show the hierarchy level of tasks and highlight parent tasks and their subtasks.
- Click
to display the details of a parent task. Click
to minimize the display.
Resource: Participant to whom a task is assigned.
- You can assign a task to a participant in the Properties Inspector. You can also click and drag the relevant participant from the list of active participants to the resource-planning schedule.
Task schedule
Timescales
- The top of the schedule displays two timescales, monthly and weekly.
- To see the details of tasks for the month or week, click the month or week when the cursor changes to
. The display of the resource-planning schedule will also be modified.
- Click
in the toolbar to change the scale or click
to return to the default display.
Task color
Color | Type of task | Description |
---|---|---|
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Not started |
|
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In progress or completed |
|
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Late |
|
- To define:
- The start date of a task: Move it horizontally in the task schedule.
- The duration of a task including its end date: Resize it horizontally in the task schedule.
Visual references
Current date
Project end date
Display of different types of tasks
Milestone : Visual reference point in the project life cycle with a null duration.
- Only its name is modifiable.
Parent task : Task containing subtasks.
See the example.
- The task may belong to a parent task.
- It cannot be modified. Its scheduled period is automatically updated each time the start date of its first task or the end date of its last task is modified.
- It can be moved to another period. In this case, all subtasks will automatically be moved.
- It can be deleted if no subtask is in progress. In this case, all subtasks will automatically be deleted.
Non-assigned task : Task not yet assigned to any resource.
- It can be moved to another period.
- Its scheduled duration can be modified.
Assigned task not yet started : Unstarted task assigned to the participant displayed in the box.
- It can be moved to another period.
- Its scheduled duration can be modified.
Assigned task in progress : Task being performed by the participant displayed in the box.
- The green bar at the top of the box shows task progress. It is automatically updated each time participants enter their time sheets.
- It can no longer be moved to another period.
- Its scheduled duration can be modified.
Assigned task completed : Task fully completed by the participant displayed in the box.
- The green bar at the top of the box extends over the entire task. The rate of progress is 100%.
- The task can no longer be modified.
Resource-planning schedule
Timescales
- The top of the schedule displays two timescales, monthly and weekly.
- To see the details of resources assigned for the month or week, click the month or week when the cursor changes to
. The display of the task schedule will also be modified.
- Click
in the toolbar to change the scale or click
to return to the default display.
Assigned resource color
Color | Description |
---|---|
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Current project tasks |
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Other project tasks and actions in the Operation and Transition menus |
Resource: List of participants in the project.
- Active participants are displayed in black.
- Currently inactive participants who played a role in the project are grayed out.
- Tasks cannot be assigned to inactive participants.
- Click
to display the details of a participant's task. Click
to minimize the display.
- To assign a task to a resource, click and drag the task from the task schedule to the resource-planning schedule.
- To activate the click and drag function, click and hold for two seconds before dragging the task.
- The cursor will change and display the availability of resources.
Cursor | Example | Description |
---|---|---|
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The task can be assigned to the resource next to the red box |
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The task cannot be assigned to the resource next to the gray box |
Properties Inspector
Access: Click a task
Task: Name of the task.
Scheduled Start/Scheduled End: Scheduled period for task completion.
- To modify it, move the task or resize it horizontally in the task schedule.
Resource: Participant to whom a task is assigned.
- The list will only display active participants.
- To assign the task, you can also click and drag the task to the resource-planning schedule.
Scheduled Workload: Scheduled time for task completion, to be performed during the scheduled period.
- Expressed in hours:minutes.
Hourly Costs: Hourly cost of the task. This may include the cost of the participant, equipment costs, etc.
- Total estimated cost of the task = Hourly cost * Scheduled workload.
- By default, the hourly cost is the one defined for the resource in the Participants tab of the Project form.
Estimated expenses: Estimated fixed costs excluding participants. This may include travel expenses, cost of equipment usage, site rental, etc.
Expenses: Actual fixed costs incurred for task completion, excluding the cost of participants.
% Progress: Task completion progress.
- Update: Automatically, each time time sheets are entered.
Comment: Comment describing the task.
Procedure: How to plan a project using the Gantt chart
Step 1: Displaying the Gantt chart of the project.
1. Select Projet > Project > My Projects or Projet > Project > Project Portfolio > My Projects in the menu.
The list of projects will appear.
2. Click next to the one you want.
Opening via the Project form
- Click
next to the Project field.
- Select the
Display Gantt option.
Step 2: Adding the relevant resources to the project.
1. Click .
2. Enter the first letters of the user name and select the user you want.
2. Click Add.
2. Repeat this procedure to add other project participants.
Step 3: Creating tasks.
1. Click .
- The new task will appear in a blue box.
- It is placed in the current date's schedule with the duration of one working day.
You should first select a task in the list. This way, the new task will be created below the selected task with an identical duration, period and hierarchy level.
2. Click the new task in the list or schedule.
3. Specify the required information in the Properties Inspector.
4. (optional. Note: Only in the schedule) Specify the task completion period.
- Click and drag the task horizontally and place it on the start date.
The new position will be indicated by a gray box.
- Release the task.
- The scheduled start date will be updated in the Properties Inspector.
- The new period will be indicated by a gray column in the schedule.
5. (optional. Note: Only in the schedule) Specify the task duration.
- Click to select the task.
- Move the cursor over the right handle of the box
.
- Resize the box
up to the end date of the task.
The scheduled end date will be updated in the Properties Inspector.
6. Repeat this procedure to create the other project tasks.
Step 4 (optional): Creating milestones.
1. Click .
You should first select a task in the list. This way, the new milestone will be created below the selected task.
Step 5 (optional): Creating parent tasks.
See the example.
1. Select the first subtask in the Task list.
2. Click .
- The WBS of the subtask will be renumbered.
- In the task schedule, a parent task will be created with a period identical to the subtask.
3. Select the second subtask.
4. Click .
The period of the parent task will be extended up to the end date of the second subtask.
Step 6: Assigning tasks to resources.
Via the Properties Inspector
1. Click the task.
2. Select the participant who will complete the task from the Resource drop-down list.
3. Press <TAB> on your keyboard to move to the next field.
4. Click .
The resource-planning schedule will be updated.
Via the resource-planning schedule
1. Click the task from the Task list and hold it for two seconds to activate the click and drag function.
2. Drag the task to the resource-planning schedule found in the bottom half of the screen.
will appear next to the cursor
when the task can be assigned to a participant.
- The position is indicated by a red box.
3. Release the task.
The resource-planning schedule will be updated.
4. (optional) Modify the order of tasks.
- Select the task you want to move in the Task list.
- Click
to move it up or click
to move it down.
- The WBS will automatically be renumbered.
- The task schedule will be updated.
Step 7: Saving the Gantt chart.
1. Click .