As you've discovered, you can only have 1 predessor- successor link going
into a task. You could use a hammock task (see the references in help) to
set the duration of your task 2 but it's something you need to be careful
with as they can be a little tricky if the task is linked to others.
I have to say I get a bit uncomfortable when I see people using fixed
duration tasks to any great extent. A task is a package of physical
activity performed by a resource over an observable time interval that
results in a deliverable. The length of time the task takes is determined by
how long it will take the resource to do the work. If he works faster it
will take less time - if he has other demands on his time during the time
the task is going on, it will take longer. Your project plan should take
such variables into account but fixed duration says it should not. Fixed
duration means just that - no matter how much work is required or how fast
the resource does it, the duration won't change. IMHO, fixed duration tasks
should be used for things like a test that has to run for a specific period
of time or the time required for concrete to cure, that sort of thing. It
would be extremely rare for actual normal human work to be fixed duration
because humans are so variable.
Anither problem is a single task that runs for 1 year! That's a long time
for someone to be working on one discrete thing. An often suggested rule of
thumb is the "8/80 Rule," meaning if your durations are less than about 8
hours you may be trying to micromanage to excess but if they're running over
80 hours you're probably not breaking down the work into small enough
packages.
HTH
