In Project, set up 2 tasks which can occur in any sequence but no.

[Gil @ IBM]

I need to set up two tasks which can occur in any order, but not at the same
time. Both have the same predecessor task and they also have the same
successor task, it is just that I cannot tell at this point in time the exact
sequence in which the two tasks will occur. For example, let's say you have
to perform two hardware installations in different cities -- you know you
cannot be in both sities at the same time, but you have not yet scheduled the
installations and do not the the exact sequence at this point in time. The
only way I can think of to establish this relationship is to set up 2 task
with one week of work effort and put the assigned resource at 50% so the 2
weeks. Is there a better way?

 

[Steve House [MVP]]

I'd set them up as two separate tasks with their durations reflecting their
expected true duration. Initially they will be in parallel but don't panic,
we'll sort that out in a moment. Let's say they are tasks number 2 & 3 out
of a set of 4 tasks. One set of links goes 1->2->4 and a second set goes
1->3->4. Assign the same resource to both 100%. He'll be overallocated.
Now resource level him. One of those tasks, probably 3, will move out until
clear of the other one, staggering them so they don't conflict. Once you
know which of those two would be preferred to happen first - maybe the
flight schedules to the city where the work will be are more convenient for
example - set its task priority to the something higher than the other
one's. Remove the leveling and relevel. Now once again they will be
staggered but with the higher priority task, whichever it is, scheduled
first.