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[bigpicture] Gantt task randomly moves start/end dates


I have a strange bug with the Bigpicutre plugin and I believe it is related to how I configure my JIRA Task or Gantt SubTask

I will create some JIRA Tasks and Subtask from the Gantt Layout page and move the task to desired start dates as well as resize the task to the desired end date using the "double arrow" at the edge of the task.

I alight the task and sub-task to my likeing and I leave.

Issue: When I come back, sometimes my task have moved to different days then what I had set. Sometimes they will have changed in lenght (for example I have task over 4  days and it will randomly change to 6 days).  Sometimes when I move the task back to the start date it originally it will automatically move all other subtask all over the place.

My process is a follow

1) Create JIRA task

2) place JIRA task on start date and resize task to end date

3) create Gantt SubTask while selecting the JIRA task.

This convers the JIRA task into a black bar and places to subtask under it.

4) Move the subtask to the start date and resize the end date

Repeat step 4 until all my subtask are added to the parent JIRA task and placed in their respective start/end date


What do I need to configure to lock the tasks so that they don't randomly move or resize themselves?




6 answers


are you sure that you don't modify start date and end date when you see edit screen of issue?

I haven't got such problem yet.

%100 percently sure that I didn't change anything :)

end-to-end links do not work in different projects as well



BigPicture features quite a few smart/automatic features, which could make some changes - of course you can disable all of them . As a rule of thumb, it is recommended to select "Manual" when creating a new Program if you want these to be turned off by default.


Each issue on the Gantt has two edges, left and right, representing its start and end date. The dates you specify in JIRA are simply imported, and hence once you just add a task it will appear where you tell it to. Now, moving this issue left or right changes the position of the start and end dates, so these are updated. Therefore the cause for date changes is actually the fact, that the issue was moved on Gantt.


This could happen if:

A) It was linked to another issue. Linked tasks have to follow certain relations dependant on the link type, and if you move one task, the linked one can very well be automatically moved to respect the given relation. More: Task Links#Auto-scheduling

B) You have the WBS synchronizers set in the Program settings. These automatically build a hierarchy based on what you choose (for instance, if you choose Project and Epic, everything will be sorted into Projects and then Epics). If WBS are on and a new task is added, it will be put accordingly to this structure and therefore may be altered by the mechanism. More: Gantt synchronization

C) The tasks or tasks that were changed were made sub-tasks of other tasks, and then the parent was moved or changed. Parent-child is a relation and children cannot take more or less time than the parent.


If the given task is on multiple Gantts (Programs), a change on any of those can result in the 3 reasons I have just mentioned.

Hi @Matthew


unfortunately I can't access the linked documentations. Could you please provide a new link to that documentation? 



Hi ,


I am also facing the same issue?.


Can somebody help?

@PhilJ ,


Did you resolve the issue?

Dear Friends,

We have the same problem too. But it occurs when we follow the below steps:

1- Opened a TASK and assigned an end date:10.01.2020

2- Generate a sub-task and assigned an end date: 8.01.2020

If there is a big Picture program of that project; the system automatically updates the main "TASK" 's end date as "8.01.2020".. 

BUT; if we generated 2 sub-tasks; the end date of main task is updated as the "latest" end date of the corresponding sub-tasks...

We couldn't understand why this is happenning? Can anyone help us too?

@seyma kudal @sarath sasi  I faced the same issue and figured it's because of the "task mode" , default is auto bottom up i.e (Parent in “auto bottom-up” adjusts automatically based on its children). Changed the mode to "manual" in settings to avoid any automatic updates to start date/time due to dependent tasks.

Hope this helps !

For more details about task mode -

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