Initialize the data problem

This is to set another kind of data

Hello Dangxiaowei,
Thank you for sending the screenshots. It seems that I confused the link type. When I tried to use the SF link, I reproduced the issue:
https://snippet.dhtmlx.com/kt49mse2

However, it is not clear to me how to check the expected behavior in MS Project.
I added a few tasks and turned on highlighting the critical path and showing slack. But for some reason, none of the tasks are critical, all of them have 0 slack days:

Could you clarify how to reproduce the use case with critical tasks in MS Project? Or you can send me a simple test file so that I can investigate it.


Hello Yansen,
It should be related to the same issue. Could you send me a test MS Project file so that I can reproduce the issue locally?

total_slack_example.mpp (247.5 KB)

the project product version is project professional 2016 (chinese ), it is Trial version,We receive it from internet,You can do that, too。

According to my own analysis, the reason why the total time difference between dhtmlx and project under SF relationship is different is that for the pre task of SF relationship, dhtmlx believes that this pre task has only one post task, that is, the task with which it has SF relationship; Project and other products (P3) believe that there are two post tasks of this pre task, one is the post task with SF relationship, and the other post task is the node connected to the nearest critical path (for example, the virtual end node of the project). Both calculate the results, and select the minimum of the two values as LS and total slack of the task That’s the difference. Please check it carefully.

Hello,
Thank you for sending the example and for the explanation. Yes, it seems that MS Project relies on the difference between the Early start and Start parameters for the Total Slack calculation. But as soon as you move the task, both parameters obtain the same value, and Total Slack becomes 0 regardless of the dates.
The Free Slack value seems to be fixed regardless of where you move the task.

In DHTMLX Gantt, the Total Slack value is obtained from the successor. It should be correct for all link types except for the Start to Finish.
So, in the following snippet, task #3 should have 0 days for the Free Slack (because it will affect its successor) and 2 days for the Total Slack(because it will become a critical task after 2 days).
Task #4 should have 4 days for the Free Slack and Total Slack because it doesn’t affect its predecessor and will become a critical task after 4 days.
https://snippet.dhtmlx.com/6akjbn1o

I added it as a bug to our internal bug tracker. The dev team will fix it in the future, but I cannot give you any ETA.

Thank you, but we still hope to get the repair version and release date of the bug. When you get the repair date, please inform us as soon as possible. Thank you. In addition, it would be better if we could add four times of the task: the earliest start time, the latest start time, the latest start time and the latest completion time. These values are required in our project, and they are available in general tool software. Please consider whether you can let them go!

This kind of bug will also appear among SS related tasks. Such a problem will occur as long as the duration of the predecessor task is longer than that of the successor task.

Hello,

Thank you, but we still hope to get the repair version and release date of the bug. When you get the repair date, please inform us as soon as possible.

Periodically, we notify about the fixed bugs, so eventually, we’ll inform you that the bug is fixed.
Unfortunately, I cannot give you any ETA on when the bug is going to be fixed.


In addition, it would be better if we could add four times of the task: the earliest start time, the latest start time, the latest start time and the latest completion time. These values are required in our project, and they are available in general tool software. Please consider whether you can let them go!

I added your suggestion to our internal wishlist. The dev team will think about adding the date properties and the implement the feature of using them in the critical path and slack calculations.


This kind of bug will also appear among SS related tasks. Such a problem will occur as long as the duration of the predecessor task is longer than that of the successor task.

Thank you for letting me know about that bug. I added that information to our internal bug tracker. The bug will be fixed in the future, but I cannot give you any ETA.