Redmine

Related to is just a lazy relation, it will not have any effect whatsoever other than showing links between the 2.

Blocks does what it says, i.e. if A blocks B, you won't be able to change B to a closing status unless A is.

Precedes is just the back relation of follows.

Behavours :

• duplicates
  If issue B is the duplicate of A
  - closing B will let A open
  - closing A will close B
• follows
  If B follows A (ex A ends the 21/04 and B begins the 22/04)
  and you add +2 day at the ending date of A,
  the starting and ending dates of B will be +2 too.
• blocks
  If issue B blocks A,
  A can't be closed unless B is.
• precedes
  If B follows A, you can't give B
  a starting date equal or less
  than the ending date of A
• related to
  ???

Again: Related to does nothing to any parts of the workflow the affected issues.

So, what is it useful for ?

Just lazily linking issues?

Thanksa a lot.

I will open new threads if you think that those following questions aren't meaningless.
Irrelevant questions :

1/ In the case of a multi-projects management, is there a mean to have a discontinued display :

  day      M T W T F - M T W T F - M T W T F - ...
Project 1  x           x           x
Project 2    x           x           x
Project 3      x           x           x
Project 4        x           x           x
Project 5          x           x           x

because I just can have

  day      M T W T F - M T W T F - M T W T F - ...
Project 1  xxxxxxxxxxxxxxxxxxxxxxxxx
Project 2    xxxxxxxxxxxxxxxxxxxxxxxxx
Project 3      xxxxxxxxxxxxxxxxxxxxxxxxx
Project 4        xxxxxxxxxxxxxxxxxxxxxxxxx
Project 5          xxxxxxxxxxxxxxxxxxxxxxxxx

2/ Is there a plug-in showing the link between the issues.

I suppose you are talking about the GANTT chart? Not sure what you mean with point 1, but I remember a ticket in which a GANTT rework has been announced with graphical links between linked issues and even I think the possibility the change the start and end dates by dragging the ends of the GANTT bars.

Thanks

About the first point, I mean that if you work 4 weeks on Project 1 but only monday of each week, the GANTT chart show a 4 weeks continued activity. I would like to have the project showing activity monday and clear the other days. Redmine is okay to count spent time but it would be clearer.
Another way could be to display a symbol for each spent time on the GANTT.

To bad I don't understand this programming language. Unfortunately, I only know the framework WinDev.