Task Duration when using non standard calendar for one resource

[GreenMonster]

I have a tast that is going to take 371.5 total hours.
I have 5 resources set up to work from 8-5 monday - friday.
I have an additional resource set up to work 5:30 pm - 10:30 PM monday -
friday and also 7:00 am - 3:00 pm on saturday.

When assigining the 5 resources (8-5 Mon-Fri) to the task the duration
changes from 371.5 hrs to 77.81 hrs. Which is what I would expect.

However, when I add the sixth resource (5:30-10:30 Mon-Fri, 7:00-3:00 Sat)
the task duration increases to 128.67 hrs.

Why does the duration increase with the one additional resources assigned to
the taks rather then decrease? Won't the task take less time since the one
resources can work an additional 5 hours per day Mon-Fri and 7 hours on
Saturday?

 

[DonL]

GreenMonster,

I think that you might be confusing Work with Duration. Duration is simply
the time period from when resources start on a task until it is complete.
Work is the effort that is necessary to complete a given task, and I think
that this is the field that you are referring to, and can add to your table
view to see this information.

Hope this helps!

 

[GreenMonster]

I'm still confused. I understand the difference between work and duration
however if the number of task resources increases doesn't the task duration
decrease?

If I change the calender of resource 6 (5:30-10:30, 7:00 - 10:00) to the
same calender of the other five resources (8-5 Mon-Fri) then the task
duration and task work behave as expected.

Calendar 1 (all six resources working 8-5 Mon-Fri)
Task Duration = 371.5 hrs (before assigning resources)
Resource 1 = 59.1hr
Resource 2 = 59.1hr
Resource 3 = 61.65hr
Resource 4 = 62.98hr
Resource 5 = 64.33hr
Resource 6 = 64.33hr
Task Duration after assigining resources = 64.33hr

Caledar 2 (5 Resources working 8-5 Mon-Fri, 1 Resource working 5:30-10:30
Mon-Fri and 7:00 - 3:00 on Saturday)
Task Duration = 371.5 hrs (before assigning resources)
Resource 1 = 59.1
Resource 2 = 59.1
Resource 3 = 61.65
Resource 4 = 62.98
Resource 5 = 64.33
Resource 6 = 64.33
Task Duration after assigining resources = 128.67 hrs

The 128.67 doesn't make sense...at least not to me. Does this help explain
my problem any better?

Thanks

 

[Mike Glen]

Hi GreenMonster ,

Welcome to this Microsoft Project newsgroup

As you have discovered, it is the odd resource that's causing the problem.
This is because he is only working 5 hours per week day (which is what the
Project calendar is measuring), this equates to 25 hours per week. To do
the 60 odd manhours of Work would give a Duration of roughly double the
Duration of the other resources working at about 40 manhours per week. This
is approximate arithmetic - Project does it accurately Have a look at
the Resource Graph or Resource Usage views for that resource to see the
daily allocation of manhours.

FAQs, companion products and other useful Project information can be seen at
this web address: http://project.mvps.org/faqs.htm

Hope this helps - please let us know how you get on

Mike Glen
MS Project MVP

 

[GreenMonster]

Thanks Mike-

The more I looked at it last night and the more I thought about it, it
started to make sense as to why the duration increase rather then the
decrease I was expecting. It still doesn't make complete sense but I'm
starting to understand why the increase occures.

Thanks to everyone for the help.

 

[Mike Glen]

You're welcome, GreenMonster

Mike Glen
MS Project MVP

 

[Steve House [Project MVP]]

Not necessarily. Imagine a task with one resource on it, starting Mon 8am
and going for 40 hours. It finishes Friday 5pm. The duration is 40 hours,
the work is 40 hours, task is effort driven. I ass a second resource but
this guy doesn't work M-F, 8-5. He's a parttimer who works Fri, Sat, & Sun
10 hours per day, 7am-6pm. Each resource now does 20 hours of the work.
Resource 1 works on the task M, T, W, T. Resource 2 works on it Fri and
Sat. The task now starts Mon 8am and finishes Sat 6pm, later than it did
before. But the duration is 4 days not 5!