C
crook
One of our PMs sent me an interesting project to look at yesterday.
The project was a modified version of one of our templates. The
template consists of ~50 tasks linked together, but without durations,
work or resources. All tasks are fixed units, effort driven, ASAP
tasks with no constraints. Not all tasks are linked together leading
to groups of tasks linked to one another independent of other groups of
tasks. Our PM had deleted some of the template tasks he didn't need,
preserving the links among a particular group of linked tasks.
When the PM started adding work and resources, the duration of one of a
group of 14 tasks changed from 1 day to 2 days (the 3rd task in the
group if it makes a difference). When the task duration changed,
Project Pro threw an error saying that "the task could not be
completed in the time allocated because there is a scheduling conflict
between this task and another one to which it is linked". Total
slack for this task and the others in its linked group went from 31.5
days to -1 days. I checked for constraints on the linked tasks, there
were none. Some tasks had resources, some did not.
What I did to fix the problem was as follows: 1) disconnect the
predecessor of the last task in the group (that task had no successor),
2) change the duration of the first task in the linked group from 0.5
days to 1 day, then back to 0.5 days. 3) reconnect the last task.
Then the duration of the task that originally caused the trouble (or
any other in the group) could be changed at will without any error
messages.
My question is twofold, what caused the error and how can I prevent a
reoccurrence in the future?
Any ideas?
The project was a modified version of one of our templates. The
template consists of ~50 tasks linked together, but without durations,
work or resources. All tasks are fixed units, effort driven, ASAP
tasks with no constraints. Not all tasks are linked together leading
to groups of tasks linked to one another independent of other groups of
tasks. Our PM had deleted some of the template tasks he didn't need,
preserving the links among a particular group of linked tasks.
When the PM started adding work and resources, the duration of one of a
group of 14 tasks changed from 1 day to 2 days (the 3rd task in the
group if it makes a difference). When the task duration changed,
Project Pro threw an error saying that "the task could not be
completed in the time allocated because there is a scheduling conflict
between this task and another one to which it is linked". Total
slack for this task and the others in its linked group went from 31.5
days to -1 days. I checked for constraints on the linked tasks, there
were none. Some tasks had resources, some did not.
What I did to fix the problem was as follows: 1) disconnect the
predecessor of the last task in the group (that task had no successor),
2) change the duration of the first task in the linked group from 0.5
days to 1 day, then back to 0.5 days. 3) reconnect the last task.
Then the duration of the task that originally caused the trouble (or
any other in the group) could be changed at will without any error
messages.
My question is twofold, what caused the error and how can I prevent a
reoccurrence in the future?
Any ideas?