Re: Planner-list predecessors for fixed date tasks

[Ricardo Fernandez <ricardo fernandez aznetwork fr>]

Hello Pete,

I'm not sure to understand, but my comment could help.

if you have a "Deadline" task  for a part of your project (including, for exemple, task A)
 - you can set "Deadline" task as a fixed date milestone
 - of course you can't set any predecessor for this fixed date task
 - so you can't set A as predecessor (for example "end to start" link) for "Deadline" task, but...
 - you can set "Deadline" task as predecessor (same example ; "start to end" link) of A

limits for this example :
 - even if A is an "as soon as possible" task, it will be scheduled to "the last moment" before "Deadline". why ? we just wan't it to become a "not after" task.
 - you can't anticipate A setting it to fixed date (today for example). why ?
 - you can't set any other predecessor to A (a current task ending tomorrow, linked "end to start", for example), even if A has been scheduled on next year. why ?

I agree that external constraints are decisive in project scheduling and that Planner constraints rules are too much restrictive.
but it's not an easy problem, and coding realy accurate rules could be an infinite task.

so just try to use such links with parsimony

Regards,
Ricardo FERNANDEZ

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De :  Alexandre Franke <alexandre franke gmail com>

Envoyé :  25/10/2009 13:14:00 +0100

À :  planner <planner-list gnome org>

Objet :  Planner-list predecessors for fixed date tasks

On Sun, Oct 25, 2009 at 5:42 AM, pete davidson <caitifty gmail com> wrote:
  

Hi all
    

Hi,

  

I'm trying to use Planner to manage academic grant applications.  As such,
there's a number of key tasks whose dates are externally set and
non-negotiable (such as the date the grant must be submitted to the funding
agency, or the date a letter of intent is due to the funding agency).  I've
been 'locking' these dates by creating a milestone task (eg "Submit grant")
with a schedule of 'on fixed date' on the required date.

The problem I'm having is when I try and link these milestone tasks to the
rest of the tasks in the project by setting a predecessor.  This produces
the error "You cannot add a relationship to a task with a Must Start On
constraint."  I've also tried using a one-day task instead of a milestone
task, but get the same error.
    

The problem here is with the meaning of the predecessor relationship.
If you set A as a predecessor of B, it means that you cannot start
working on B until A is done. So what would happen if you start A on
oct 26th, need 4 days to finish it and set B on oct 28th (fixed date)?
That wouldn't make any sense because you'd need to work on B but you
couldn't since A isn't done yet.

This has nothing to do with the fact that it's a milestone.

  

Is there another approach to dealing with externally set fixed dates that
I'm missing, or a way to set milestone tasks which allows linking to other
tasks?
    

You can do it without the predecessor relationship, I think it's the
way that would make the most sense.