WBS and the Gantt chart
As we could already notice, BigPicture's Gantt module is divided into two major sections: a list of tasks including the WBS (Work Breakdown Structure):
and the Gantt chart - a timeline with cards represented as taskbars:
Tasks and task-related actions
As our add-on functions within Trello, it uses very similar concepts of workload units as the environment it operates in. And as mentioned before: Cards have to be somehow represented on the Gantt chart. This paragraph will focus on Tasks and Sub-Tasks as a reflection of out Board Cards and actions which we can perform with them on our Gantt Chart.
A concept of an Artificial Task (coming soon!)
Now, this is new! What are the Artificial Tasks? They are nothing more but tasks added to the Power-Up's - Gantt chart (and columns of Gantt's WBS Waterfall Panel) yet not reflected in Trello whatsoever. They can perfectly coexist with Trello Cards presented on our Gantt chart and on Gantt's WBS like the rest of Trello's native task units and go under the same set of rules (including linking, sorting etc.). We can create and set Artificial Tasks to be visualized as regular Tasks or Sub-Tasks.
In order to create an Artificial Task, please select the '+Task' from the drop-down menu at the top left of the Gantt screen.
Creating Tasks (coming soon!)
If we decide to add a Task from the Gantt Chart itself, it will always be an Artificial Task. It will bring up a pop-up window with issue's Summary, Start and End Dates. Filling out these fields, followed by pressing the 'Save' button will automatically allocate the Artificial Task on the Gantt chart and on the Gantt WBS, yet will not affect our Trello Board. Creating an Artificial Sub-Task though will add the same sort of workload unit yet it will be automatically indented under its parent.
One on the Gantt charts timeline, when we highlight the desired task, small circles to the left and right side of that task will appear. Dragging to the circle of another task and dropping it there will create a dependency between these two tasks. We can only perform a single drag and drop operation at a time, and each task (the one we start at and the one we end at) has two sides. This means there are four kinds of visual links (in a form of an arrow).
Four Types of Links
As mentioned - every task on the Gantt chart has two significant sides - to the left and to the right. These symbolize the Start and End Dates. Therefore, by linking two tasks (below referred to as the Task A and Task B) we can expect four possible combinations:
This means that when Task A starts, Task B will also start.
When two tasks are connected this way and task A is moved to the left, task B remains unchanged. When Task A is moved right and exceeds the Start Date of Task B, then Task B will also be moved to the right in order to start at the same time as Task A.
When Task B is moved to the left, it will never go further than the start date of Task A. If Task B is moved right, Task A remains unchanged.
When Task A starts, Task B will immediately finish.
In this type of dependency, when Task A is moved totheright,ifits Start Date exceeds the End Date of Task B, B will be also moved right. Moving Task A to the left changes nothing.
When Task A finishes, then Task B starts.
Moving Task A to the right will also move Task B, as long as Task A's End Date is moved up to or ahead of Task B's Start Date. Moving Task A to the left has no effect on Task B. When Task B is moved to the left, it will not go further than Task A's End Date. Moving it to the right has no effect on Task A.
When Task A ends, Task B also immediately ends.
Moving Task A to the left changes nothing. However, if Task A is moved further than Task B's End Date, Task B will be moved in order to retain the dependency (and to end at the same time). Moving Task B to the left further than Task A's End Date will automatically move Task B's end at the same time as the end of Task A. Moving Task B to the right has no effect on Task A.
To change the link type between two tasks you can also click on the link and select a different one in the "Type" section.
Once this checkbox is marked the link will always set:
the earliest possible Start Date of the linked target task if Start Date is the target
the earliest possible End Date of the linked target task if End Date is the target.
In other words - link in ASAP mode always schedules target task as soon as possible based on dependency type. There are no restrictions on how many links are created for each source or target task as long as they are not creating a circular relationship (discussed here). If a task is moved to a prohibited position (based on link type and mode) it is moved back/forward to the appropriate position.
Setting up the Lag Time and Deleting Dependency
By clicking on the 'Link Arrow' we are given a possibility to set the Lag Time which is a minimal number of day between tasks before the dependency rules will be manifested. If the minimal required amount of days is not met by the tasks' Start and End Dates, they will get rescheduled.
Please note that lag time is the minimum distance, not the exact required one. If we set a lag time of 1 day for tasks that have 3 days between them, nothing will happen - the gap will not shorten to a single day as it still meets the initial requirement.
As we can see above, this menu not only allows us to set a lagtime,but also to 'Delete' a link and/or change the Type of dependency to a new - desired one from a drop-down menu at the very bottom of the pop-up.
Loops and Cross-Program Relationship
In BigPicture, task links have a direct effect on the Start and End Dates, so some combinations of links will not be allowed. This concerns what we call "loops". Let's imagine the following type of inter-dependency:
Task A (Ends) → (Starts) Task B
Task B (Ends) → (Starts) Task C
Task B (Ends) → (Starts) Task C
Please note that the same effect can be achieved using only 2 tasks.
Such a combination of links on these tasks would result in Task A rescheduling Task B, Task B rescheduling Task C, Task C rescheduling Task A, and so on and so forth. This sort of paradox would create an infinitive number of re-calculation and could possibly crush our environment. This is why our app Power-Up will not allow it and will return a Warning.
Task Structure Adjustment
There's a number of ways we can adjust the structure of tasks on our Gantt chart and Gantt's WBS. One of our Power-Up's core features - its capability to alter tasks' values by moving them around with simple drag and drop mechanics can be used not only in the sphere of ourGantt's diagram but also on the Gantt's WBS. This way we can adjust the allocation of tasks and their hierarchy.
The other method is the method of manual indentation.
Up and down arrows simply move a task inside its current node. For instance, if a task is a subtask of an Epic, we will only be able to move it up and down inside this Epic's tier.
Left and right arrows are responsible for indent and outdent operations, meaning to shift tasks into Sub-Tasks or parents of ones that follow.
As a result, if we would like a Sub-Task to go under a different parent, we need to follow this procedure:
- Outdent the task, so it moves to the same tier as its previous parent.
- Move the task down so it's just below the new parent.
- Indent the task.
Task Context Menu
As we will learn later in this documentation, many tasks based data and display operations can be applied globally (for each task in the whole Program / Gantt). Yet there are cases in which we would like to apply such adjustments for each task separately. This is whatTaskContext Menu is for. It allows us to switch Task Types (switch them into Milestones) or Task Modes, Provides different sorting options or gives the possibility to manually change its Color.
As BigPicture is customizable on many levels, it also offers modifications in terms of the display along with the range of data which can be filtered out for our convenience.