Limiting the number of simultaneous tasks

[Gilgamesh]

Hello,
I have a series of almost identical tasks (over 300) where the only
difference is a resource assignment and some work hours.
I was wondering if there was a way of limiting the number of these that
occur simultaneously to 3 without setting up a lot of predecessor
relationships.

I know I can add a resource to the task and resource level but this changes
the work value on the task and the work hours is something we track by so
this is not desirable. I was thinking I might be able to add a material
resource for this but haven't been able to figure out the right way.

Thank You

 

[Dave]

What algorithm would you wish to apply? That is essentially what your
question comes down to. If it is arbitrary which 3 tasks can occur
together, then VBA could be used.

Why don't you want more than 3 tasks worked on simultaneously? If you
want to reserve resources for other activities, then you could reduce
their allocation units accordingly and level (or include those
activities in the plan or other pooled plans).

I think that if we were to understand better the true constraint that
underpins your question we might be able to help better.

Dave

 

[Steve House]

Material resources won't do it because material availability doesn't affect
the schedule (unfortunately). But it's confusing when you say you don't
want to assign resources because you track the work hours and assigning
resources changes them. Work doesn't exist except in the context of
activity performed by a resource. If I say a task has a 3 day duration but
there are no resources assigned, the number of man-hours of work that will
be done during that 3 day period is completely indeterminate. It might be
one guy working slowly doing 3 man-hours of FTE work over the course of 3
days, it might be a crew of 10 doing a total of 240 man-hours of work over a
period of 3 days, or something in between, you simply don't know. It is
actually impossible to really track work hours without assigning resources!

 

[Gilgamesh]

Material resources won't do it because material availability doesn't
affect the schedule (unfortunately). But it's confusing when you say you
don't want to assign resources because you track the work hours and
assigning resources changes them. Work doesn't exist except in the
context of activity performed by a resource. If I say a task has a 3 day
duration but there are no resources assigned, the number of man-hours of
work that will be done during that 3 day period is completely
indeterminate. It might be one guy working slowly doing 3 man-hours of
FTE work over the course of 3 days, it might be a crew of 10 doing a total
of 240 man-hours of work over a period of 3 days, or something in between,
you simply don't know. It is actually impossible to really track work
hours without assigning resources!

Hello,
It seems that I was not very clear when explaining the task.
The tasks in question have resources assigned that are there to do the work
and there are different resources on the different tasks. I was thinking of
adding a dummy resource with a max value of 300% and levelling so as to
limit the number of simultaneous tasks to 3 but adding this dummy resource
unfortunatly changes the work value that is set for the other resources on
the task.

--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs

Hello,
I have a series of almost identical tasks (over 300) where the only
difference is a resource assignment and some work hours.
I was wondering if there was a way of limiting the number of these that
occur simultaneously to 3 without setting up a lot of predecessor
relationships.

I know I can add a resource to the task and resource level but this
changes the work value on the task and the work hours is something we
track by so this is not desirable. I was thinking I might be able to add
a material resource for this but haven't been able to figure out the
right way.

Thank You

 

[Gilgamesh]

What algorithm would you wish to apply? That is essentially what your
question comes down to. If it is arbitrary which 3 tasks can occur
together, then VBA could be used.

It is not arbitrary which 3 tasks occur together, it could be any of the 300
just so long as it is no more than 3

Why don't you want more than 3 tasks worked on simultaneously?

There was a policy decision on regarding potential client impact to limit
the number of these tasks happening at any one time.

If you want to reserve resources for other activities, then you could
reduce their allocation units accordingly and level (or include those
activities in the plan or other pooled plans).

If the same resources were used on all the tasks then reducing the
availability would be the way to go but I have different resources on the
tasks. I did say I thought about adding an additional resource just for
purposes of resource levelling but this changes the work value that is
needed for the other resources on the task.

I think that if we were to understand better the true constraint that
underpins your question we might be able to help better.

The constraint is the policy decision to limit the potential client impact.


Thank You

 

[Dave]

How about going the other way - instead of creating a dummy resource
with maximum allocation units of 300%, make one with a very low maximum
allocation value. Then allocating them to the tasks will make very
little difference to the total number of hours in the Project.

I've done a quick test with this and it seems to work (not sure how
small you can make the maximum allocation units value, but you can
experiment with that).

Hope this helps.

Dave

Material resources won't do it because material availability doesn't
affect the schedule (unfortunately). But it's confusing when you say you
don't want to assign resources because you track the work hours and
assigning resources changes them. Work doesn't exist except in the
context of activity performed by a resource. If I say a task has a 3 day
duration but there are no resources assigned, the number of man-hours of
work that will be done during that 3 day period is completely
indeterminate. It might be one guy working slowly doing 3 man-hours of
FTE work over the course of 3 days, it might be a crew of 10 doing a total
of 240 man-hours of work over a period of 3 days, or something in between,
you simply don't know. It is actually impossible to really track work
hours without assigning resources!

Hello,
It seems that I was not very clear when explaining the task.
The tasks in question have resources assigned that are there to do the work
and there are different resources on the different tasks. I was thinking of
adding a dummy resource with a max value of 300% and levelling so as to
limit the number of simultaneous tasks to 3 but adding this dummy resource
unfortunatly changes the work value that is set for the other resources on
the task.

--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs

Hello,
I have a series of almost identical tasks (over 300) where the only
difference is a resource assignment and some work hours.
I was wondering if there was a way of limiting the number of these that
occur simultaneously to 3 without setting up a lot of predecessor
relationships.

I know I can add a resource to the task and resource level but this
changes the work value on the task and the work hours is something we
track by so this is not desirable. I was thinking I might be able to add
a material resource for this but haven't been able to figure out the
right way.

Thank You

 

[Gilgamesh]

How about going the other way - instead of creating a dummy resource with
maximum allocation units of 300%, make one with a very low maximum
allocation value. Then allocating them to the tasks will make very little
difference to the total number of hours in the Project.

I've done a quick test with this and it seems to work (not sure how small
you can make the maximum allocation units value, but you can experiment
with that).

That seems to work with a 1% allocation value.

Thanks

Hope this helps.

Dave

Material resources won't do it because material availability doesn't
affect the schedule (unfortunately). But it's confusing when you say you
don't want to assign resources because you track the work hours and
assigning resources changes them. Work doesn't exist except in the
context of activity performed by a resource. If I say a task has a 3 day
duration but there are no resources assigned, the number of man-hours of
work that will be done during that 3 day period is completely
indeterminate. It might be one guy working slowly doing 3 man-hours of
FTE work over the course of 3 days, it might be a crew of 10 doing a
total of 240 man-hours of work over a period of 3 days, or something in
between, you simply don't know. It is actually impossible to really
track work hours without assigning resources!

Hello,
It seems that I was not very clear when explaining the task.
The tasks in question have resources assigned that are there to do the
work and there are different resources on the different tasks. I was
thinking of adding a dummy resource with a max value of 300% and
levelling so as to limit the number of simultaneous tasks to 3 but adding
this dummy resource unfortunatly changes the work value that is set for
the other resources on the task.

--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs



Hello,
I have a series of almost identical tasks (over 300) where the only
difference is a resource assignment and some work hours.
I was wondering if there was a way of limiting the number of these that
occur simultaneously to 3 without setting up a lot of predecessor
relationships.

I know I can add a resource to the task and resource level but this
changes the work value on the task and the work hours is something we
track by so this is not desirable. I was thinking I might be able to
add a material resource for this but haven't been able to figure out the
right way.

Thank You