mathematical question

[Stefan_Sand]

Hello,

i have a nice Excel Gantt Chart (it is a xy scatter diagram) , which can be adopted by any user. The only question i have now is, if i have some linked tasks (predecessor and successor tasks).
i want the link (every link has 6 x coordinates and 6 y coordinates) between thes tasks change automatically. My problem now is, if the linked tasks are next to each other in the arrangement - task 1 to task 2 , task 3 to task 4, or task 8 to task 9 ..... my formula works very well, but if i have linked task 1 with task 6 for example, the formula doesn´t work coorect, the link is shown within the tasks between (using the example from task 1 to task 6) 1 and 6 which makes the picture ugly (see the example table).

My question is, how should the link coordinates be adopted to show the link correct in the chart for any possibility of connection)?

[Rudi]

Hi Stefan,

This looks a bit beyond my expertise...

Hans is travelling at the moment but lets see if he has any comments for you when he intermittently logs in. I hope that other Excel experts might be able to contribute to a solution here too in the mean time.

[Stefan_Sand]

thanks anyway for your look;

i guess, the formulae for the coordinates from x3 (if i start from x0 to x5) and x4 have to be adopted....

[HansV]

I'm afraid that I don't have access to the full version of Excel at the moment, so I can't comment. Sorry.

[Stefan_Sand]

So, i tested the situation with my possibillities and got a "final" solution, with some.... flaws....

I figured out the 4 possible dependencies of project tasks:

we have the common way: End to Start dependencies (EA)
End to End dependencies (EE)
Start to Start (AA)
Start to End (AE) jump sequence - rarely used in project management

i figured out a matrix for all ways of sequences (P19:AA22)
via vlookup i could get any possibility for any dependency betweeen the tasks, which works.....

is there a possibillity to do it in only one formula?

PS: the reason for this is, that i would have to do the whole possibility matrix for each dependency.

[HansV]

I have taken a look at both workbooks, but I am afraid that - not being involved in project management - I don't have the slightest idea what they do or how they work. Sorry.