Problem with constraint "as late as possible" .....

%3CLINGO-SUB%20id%3D%22lingo-sub-1898901%22%20slang%3D%22en-US%22%3EProblem%20with%20constraint%20%22as%20late%20as%20possible%22%20.....%3C%2FLINGO-SUB%3E%3CLINGO-BODY%20id%3D%22lingo-body-1898901%22%20slang%3D%22en-US%22%3E%3CP%3EDear%20community%2C%3C%2FP%3E%3CP%3EI%20am%20hosting%20a%20project%20plan%20in%20which%20I%20have%20a%20strange%20behavior%20when%20I%20am%20using%20the%20contraint%20%22as%20late%20as%20possible%22.%3C%2FP%3E%3CP%3EI%20have%20e.g.%20a%20fridge%20where%20someone%20(Person%20A)%20is%20doing%20some%20work%20on%20and%20I%20am%20the%20next%20person%20(Person%20B)%20in%20the%20row%20to%20work%20on%20that.%20For%20my%20work%2C%20I%20need%20to%20prepare%20some%20documents%20which%20I%20want%20to%20prepare%20as%20late%20as%20possible%2C%20of%20course.%3C%2FP%3E%3CP%3ESo%20the%20person%20has%20a%20part%20of%20the%20plan%20with%20his%20tasks%20which%20are%20summarized%20in%20a%20task%20called%20(ready%20for%20(next%20Step).%20The%20beginning%20of%20my%20manual%20work%20on%20the%20fridge%20might%20be%20called%20%22point%20X%22%20%3A)%3C%2Fimg%3E%3C%2FP%3E%3CP%3ESo%20wthat%20I%20have%20done%20is%2C%20that%20I%20have%20linked%20the%20summarizing%20task%20from%20Person%20A%20to%20Point%20X%20with%20a%20end-to-start%20constraint.%3C%2FP%3E%3CP%3ENow%2C%20the%20documentation%20preparation%20for%20point%20X%20should%20be%20as%20late%20as%20possible%2C%20so%20I%20give%20all%20the%20preparation%20tasks%20the%20constraint%20type%20%22as%20late%20as%20possible%22%20and%20all%20the%20tasks%20downstream%20from%20Point%20X%20%22as%20soon%20as%20possible%22.%3C%2FP%3E%3CP%3Ewhat%20now%20happens%20is%2C%20that%20Point%20X%20moves%20forward%20in%20time.%20It%20is%20no%20longer%20the%20end%20date%20of%20the%20Person%20A%2C%20but%20seems%20to%20be%20about%2014%20days%20later.%20This%20should%20not%20happen%20as%20I%20really%20want%20to%20take%20Point%20X%20as%20the%20fixing%20point%20for%20preparation%20work.%20And%20yes%2C%20Point%20X%20is%20a%20variable%20date%2C%20dependent%20on%20when%20Person%20A%20finishes%20his%20work.%3C%2FP%3E%3CP%3EWhen%20I%20set%20the%20constraint%20%22has%20to%20start%20on%20...%22%20for%20Point%20X%2C%20everything%20works%20fine.%3C%2FP%3E%3CP%3E%26nbsp%3B%3C%2FP%3E%3CP%3ESo%2C%20who%20knows%20what%20I%20am%20doing%20wrong%3F%20Maybe%20someone%20of%20you%20might%20assist%20me%20in%20a%20short%20video%20call%20as%20I%20am%20not%20sure%20If%20I%20was%20able%20to%20cleary%20describe%20what%20I%20am%20doing%20%3B)%3C%2Fimg%3E%3C%2FP%3E%3CP%3E%26nbsp%3B%3C%2FP%3E%3CP%3EThanks%20for%20your%20support%2C%20Greetings%20from%20switzerland%2C%20Oliver%3C%2FP%3E%3CP%3E%26nbsp%3B%3C%2FP%3E%3C%2FLINGO-BODY%3E
New Contributor

Dear community,

I am hosting a project plan in which I have a strange behavior when I am using the contraint "as late as possible".

I have e.g. a fridge where someone (Person A) is doing some work on and I am the next person (Person B) in the row to work on that. For my work, I need to prepare some documents which I want to prepare as late as possible, of course.

So the person has a part of the plan with his tasks which are summarized in a task called (ready for (next Step). The beginning of my manual work on the fridge might be called "point X" :)

So wthat I have done is, that I have linked the summarizing task from Person A to Point X with a end-to-start constraint.

Now, the documentation preparation for point X should be as late as possible, so I give all the preparation tasks the constraint type "as late as possible" and all the tasks downstream from Point X "as soon as possible".

what now happens is, that Point X moves forward in time. It is no longer the end date of the Person A, but seems to be about 14 days later. This should not happen as I really want to take Point X as the fixing point for preparation work. And yes, Point X is a variable date, dependent on when Person A finishes his work.

When I set the constraint "has to start on ..." for Point X, everything works fine.

 

So, who knows what I am doing wrong? Maybe someone of you might assist me in a short video call as I am not sure If I was able to cleary describe what I am doing ;)

 

Thanks for your support, Greetings from switzerland, Oliver

 

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