Dependency Handling on Inactive Tasks – Not Aligned with MPP

Post by **sagarshivgan** » Fri Mar 20, 2026 9:36 am

Hi,

In Bryntum Gantt, if we have a dependency chain like T1 → T2 → T3, and task T2 is cancelled (inactive), then T3 gets aligned to its parent’s start date.

In Microsoft Project (MPP), the same scenario behaves differently: when T2 is cancelled, T3 is scheduled after the end date of T1, effectively honoring the indirect dependency T1 → T3.

How can we configure Bryntum Gantt to replicate MPP’s behavior, so that downstream tasks continue to respect the logical predecessor chain (e.g., T1 → T3) even if an intermediate task is cancelled(inactive)?

Please find attached screenshots for reference.

Thanks & Regards,
Sagar Shivgan

Post by **Arc** » Fri Mar 20, 2026 11:17 am

Hello,

This is not supported yet.
We have a feature request but it's not resolved: https://github.com/bryntum/support/issues/3304

Best regards,
Arcady

Post by **sagarshivgan** » Tue May 05, 2026 11:53 am

Hi arcady,

Thank you for your response. I understand that https://github.com/bryntum/support/issues/3304 this request was originally raised in 2021 and is still open.

Could you please share if there is any tentative timeline for when this feature might be implemented? Knowing the expected timeframe would help me plan accordingly for my project needs.

In the meantime, could you also point me to the relevant code areas or modules where I might apply a temporary fix or adjustment until the official implementation is available? Even a high-level pointer to the right part of the codebase would be very helpful.

I appreciate your support and look forward to your guidance.

Thanks & Regards,
Sagar Shivgan

Post by **Arc** » Wed May 06, 2026 11:10 am

Hello,

We have no plans on implementing the feature yet I'm afraid.
Initially it was added due to sponsorship of one of our customers who wanted it in the Gantt. And for them it was enough it to look as it is now.

The feature implementation can be found in InactiveEventMixin class (Engine/quark/model/gantt/InactiveEventMixin.ts file), InactiveEventScheduleMixin class (Engine/quark/model/gantt/InactiveEventScheduleMixin.ts file) and ConstrainedByDependenciesEventScheduleMixin class (Engine/quark/model/scheduler_pro/ConstrainedByDependenciesEventScheduleMixin.ts file) plus some more classes that are less relevant in your case.
The last mentioned class is a candidate for changing. There inactive tasks are ignored when pushing successors.

Best regards,
Arcady