Unwanted changes when importing from MS Project

Hi !
I am quite new to GP, however like the basic idea (alternate between “Gantt” view and “Resources Chart” view) in its simplicity very much.
One of the “workmodes” I have just tested is to use GP just as a mere viewer of a project made in MS Project. (I know GP can do far more.) GP coped with MPP import quite well, both the views work well but GP automatically rescheduled some tasks on import (see logs below) :frowning:
Is there any way to make GP not do this and keep the project exactly as it was made ?
(Tested with GP 2.8.9 Pilsen (build 2335))

Warning

The following problems were detected during import. Please note that some of them may be harmless

Severity
Message
INFO
Some tasks (52 out of 200) have changed their start dates. See the details below. What does it mean?
WARNING
Task DSP CČ: was 12/6/18 12:00 AM, now 11/30/18 12:00 AM
WARNING
Task analýza scanu: was 1/3/19 12:00 AM, now 12/20/18 12:00 AM
WARNING
Task M: Připraveno na P2: was 11/29/18 12:00 AM, now 11/30/18 12:00 AM
WARNING
Task N odstranění EME1 TELE: was 11/19/18 12:00 AM, now 11/16/18 12:00 AM
WARNING
Task nástroje pro zpracování scanu: was 9/15/18 12:00 AM, now 9/17/18 12:00 AM
WARNING
Task schválení zprávy GM, předání: was 11/7/18 12:00 AM, now 11/8/18 12:00 AM
WARNING
Task analýza scanu, návrh řešení: was 9/26/18 12:00 AM, now 9/24/18 12:00 AM
WARNING
Task připraveno k nasazení: was 10/12/18 12:00 AM, now 10/15/18 12:00 AM
WARNING
Task připraveno k nasazení: was 10/18/18 12:00 AM, now 10/19/18 12:00 AM
WARNING
Task Vyhodnocení, projednání: was 1/4/19 12:00 AM, now 12/21/18 12:00 AM
WARNING
Task Vývojové prostředí: was 9/15/18 12:00 AM, now 9/17/18 12:00 AM
WARNING
Task Školení EPR2: was 10/10/18 12:00 AM, now 10/3/18 12:00 AM
WARNING
Task DSP: was 12/14/18 12:00 AM, now 12/12/18 12:00 AM
WARNING
Task testování v OSC: was 10/1/18 12:00 AM, now 9/26/18 12:00 AM
WARNING
Task M: Připraveno na P1: was 11/8/18 12:00 AM, now 11/9/18 12:00 AM
WARNING
Task předběžný návod: was 11/20/18 12:00 AM, now 11/21/18 12:00 AM
WARNING
Task MAL nasazení na místě: was 11/26/18 12:00 AM, now 11/27/18 12:00 AM
WARNING
Task připraveno k nasazení: was 11/15/18 12:00 AM, now 10/29/18 12:00 AM
WARNING
Task DSP TELE: was 11/28/18 12:00 AM, now 11/22/18 12:00 AM
WARNING
Task M: Připraveno na T: was 10/15/18 12:00 AM, now 10/11/18 12:00 AM
WARNING
Task nasazení na místě: was 11/20/18 12:00 AM, now 10/29/18 12:00 AM
WARNING
Task vše připraveno k nasazení: was 12/17/18 12:00 AM, now 12/18/18 12:00 AM
WARNING
Task Předání: was 12/14/18 12:00 AM, now 11/28/18 12:00 AM
WARNING
Task N ASRU EDS: was 11/22/18 12:00 AM, now 11/16/18 12:00 AM
WARNING
Task nasazení na místě: was 11/14/18 12:00 AM, now 10/16/18 12:00 AM
WARNING
Task uzavření smlouvy: was 11/5/18 12:00 AM, now 10/17/18 12:00 AM
WARNING
Task předání: was 10/30/18 12:00 AM, now 10/17/18 12:00 AM
WARNING
Task předání: was 10/31/18 12:00 AM, now 10/23/18 12:00 AM
WARNING
Task připraveno k nasazení: was 10/12/18 12:00 AM, now 10/16/18 12:00 AM
WARNING
Task předání: was 12/21/18 12:00 AM, now 10/22/18 12:00 AM
WARNING
Task DSP: was 11/28/18 12:00 AM, now 11/22/18 12:00 AM
WARNING
Task dokončeno nasazení: was 12/19/18 12:00 AM, now 12/20/18 12:00 AM
WARNING
Task školení 2: was 12/4/18 12:00 AM, now 11/7/18 12:00 AM
WARNING
Task Aktualizace: was 9/15/18 12:00 AM, now 9/17/18 12:00 AM
WARNING
Task nasazení na místě: was 10/23/18 12:00 AM, now 10/19/18 12:00 AM
WARNING
Task MAL předání: was 11/30/18 12:00 AM, now 11/29/18 12:00 AM
WARNING
Task funkční testy: was 11/27/18 12:00 AM, now 10/18/18 12:00 AM
WARNING
Task předání: was 11/28/18 12:00 AM, now 10/31/18 12:00 AM
WARNING
Task N ASRU EME2: was 11/23/18 12:00 AM, now 11/16/18 12:00 AM
WARNING
Task Servis RTISZ: was 9/15/18 12:00 AM, now 9/17/18 12:00 AM
WARNING
Task M: aktualizace dokončeny: was 1/8/19 12:00 AM, now 1/3/19 12:00 AM
WARNING
Task nasazení na místě: was 10/29/18 12:00 AM, now 10/15/18 12:00 AM
WARNING
Task Integrační testy CČ: was 11/8/18 12:00 AM, now 11/5/18 12:00 AM
WARNING
Task DSP, PTD, protokoly: was 11/29/18 12:00 AM, now 10/15/18 12:00 AM
WARNING
Task RPD: was 10/15/18 12:00 AM, now 10/9/18 12:00 AM
WARNING
Task příprava před 2. termínem: was 12/3/18 12:00 AM, now 11/6/18 12:00 AM
WARNING
Task DSP, PTD, protokoly: was 12/12/18 12:00 AM, now 10/29/18 12:00 AM
WARNING
Task DSP, PTD, protokoly: was 11/28/18 12:00 AM, now 10/19/18 12:00 AM
WARNING
Task N ASRU ETE: was 11/20/18 12:00 AM, now 11/16/18 12:00 AM
WARNING
Task SW realizace v OSC: was 10/8/18 12:00 AM, now 10/9/18 12:00 AM
WARNING
Task předání: was 12/19/18 12:00 AM, now 12/14/18 12:00 AM
WARNING
Task DSP, protokoly: was 12/19/18 12:00 AM, now 10/18/18 12:00 AM
This report has been written to the log file. If you send it to GanttProject developers, please attach your MS project file

You may want to read this article which explains the reasons and suggests possible remedies for some particular cases.

In common case, no, we can’t keep MS Project data as is. There are too many MS Project features which are not supported in GanttProject and naturally we can’t interpret them properly when they are found in the project files.

Oh, thank you for your fast and valuable answer, which DID help ! It was the >>dependency hardness to “Rubber”<< setting that solved the problem !

As I get deeper into the problem some troubles still persist. :slightly_frowning_face:
I can understand that MS Project and GP are different programs with different abilities and different implementation of some features.
However, I’ve found out that one of the items causing an unwanted reschedule after import from a MPP are Finish-Start dependency constraints with negative lag time. However GP seems to implement them too. So what’s the problem, is it a bug ?

Example: I’ve got two tasks linked with a Finish-Start dependency constraint with negative lag time of -2 days. In MS Project the second task’s start is properly scheduled two days before the first task ends. After import the constraint is transferred correctly (I can still see the delay of -2 days lag in task properties in GP) however the second task has been rescheduled to start as late as the first task ends ! I can shift the second task by drag and drop in GP after import to start two days sooner again but why does it happen at all ?

If you’re sure you have found a bug in the import, please file a bug report and attach a sample MS Project file. Or attach a sample file here.

I am sure GP 2.8.9 Pilsen (build 2335] for Windows behaves like described but I don’t know if it is a bug or a feature ! :roll_eyes:
Here’s a simple MPP with 3 tasks only - try to
1] open directly in MS Project
2] import into GP
and compare the Gantt view in both cases. No matter how GP is set, the rightmost task is rescheduled and shifted 2 days later.NegativeLagExample.zip (50.1 KB)

Thanks for the example.
The problem is that scheduler runs during import process and manages to reschedule your last task before import sets dependency to rubber and lag time to negative.

We’ll fix it in the next update.

Bug report for this issue: https://github.com/bardsoftware/ganttproject/issues/1602