Knock on effects of a shortened working day

[Peter Rooney]

This is a bit messy, but here goes.

I had a mini project within my plan, including the following tasks:

Task 1 Start Tuesday 26/04/05 09:00 End Friday 29/04/05 17:30 50% comp
Task 2 Start Tuesday 03 05/05 09:00 End Thursday 05/05/05 17:30 50% comp
Task 3 Start Friday 06/05/05 09:00End End Tuesday 10/05/05 17:30 50% comp
Task 4 Start Wednesday 11/05/05 09:00 End Friday 13/05/05 17:30 0% comp
Task 5 Start Monday 16/05/05 09:00 End Wednesday 18/05/05 17:30 50% comp
Task 6 Start Thursday 19/05/05 09:00 End Monday 23/05/05 17:30 0% comp
Task 7 Start Tuesday 24/05/05 09:00 End Thursday 26/05/05 17:30 50% comp

All tasks are linked and all are Start As Soon As Possibles.

I'm now trying to reduce the working day for the single resource concerned
to 5.5 hours from the current 7.5. So, I did a blanket change on her
calendar, changing the working pattern from 09:00-13:00 and 14:00-17:30 to
09:00-13:00 and 14:00 to 15:30.

The purpose of the exercise is to see by how much the project end date will
be pushed out.

Now, for the corresponding tasks, I get the following:

Task 1 Start Tuesday 26/04/05 09:00 End Friday 29/04/05 17:30 50% comp
Task 2 Start Tuesday 03 05/05 09:00 End Thursday 06/05/05 11:00 50% comp
Task 3 Start Friday 06/05/05 09:00 End Wednesday 11/05/05 13:30 50% comp
Task 4 Start Wednesday 11/05/05 14:00 End Tuesday 17/05/05 14:30 0% comp
Task 5 Start Monday 16/05/05 09:00 End Thursday 18/05/05 14:45 50% comp
Task 6 Start Thursday 19/05/05 14:45 End Wednesday 25/05/05 15:15 0% comp
Task 7 Start Tuesday 24/05/05 09:00 End Friday 27/05/05 15:30 50% comp

Original durations were 4, 3, 3, 3, 3, 3, 3
Modified durations are 4, 3, 2.73, 3, 2.73, 3, 2.73

Some of the changes I understand - some I don't - for instance, why have the
durations of tasks 3, 5 and 7 changed from 3 days to 2.73 days?

Is it something to do with the fact that they've been started - in that
case, why haven't 1 and 2 changed as well?

Whilst Tasks 2, 4 and 6 still add up to 22.5 hours, Task 5 now only adds up
to 21.25 hours, based on the start and end times shown (Mon, Tue & We @ 5.5
hours and Thu @ 4.75 hours), even though the Work for both after the changes
still shows as 22.5 hours - but 21.25 ISN'T 2.73 days of 5.5 hours' duration!

I know this is probably something really fundamental about Project that I
should understand, considering I've been working with it for 6 months, but,
sad to say, I don't. I just hope that someone out there will take a look at
how long it took me to get this in here and try to give me some basic
pointers )

Thanks (B-I-G thanks) in advance

Pete

 

[Steve House [Project MVP]]

Changing the resource's work day by itself will not affect the task's
duration directly although it may affect the task's finish date. Duration
is measured in Hours (actually minutes, to be precise) and converted to/from
days according to the entry on the Tools Options Calendar page. So task 1
was 4 days. At 7.5 hours per day that's 30 hours. Now regardless of what
happens to the resource's individual working hours, 30 hours work is going
to be 30 hours work. What will change is the number of working days it will
required her to DO the required 30 hours of work but that's elapsed time,
not duration. If she works 7.5 hours a day, she will do 30 hours over the
course of 4 work days. But if she works 5.5 hours per day, she will require
~ 5 1/2 of her work days to do 30 hours. To make sense out of the remaining
durations, convert everything into hours and deduct the number of hours that
have actually been worked, then convert that number to days according to the
"hours per day" conversion factor on the Calendar Options page, NOT the 5.5
hour per day she herself works.

Complicating understanding just what's going on here are your tasks 3, 5,
and 7. What you've described presents a physical impossibility. Task 3
starts 6 May, today, yet you show that it is already 50% complete. Even
worse, task 5 starts 16 May and you show 50% complete, and task 7 doesn't
start until 24 May and yet it too is shown 50% complete. % Complete refers
to duration - if it's anything greater than zero it means some time has been
put in on the task, work has been performed over some observable time
period. But having actual work posted against a start of 24 May implies
that the work scheduled on 24 May was PERFORMED ON 24 May - since that is
still 3 weeks in the future as of this writing, you can only do that if you
have a time machine. If you have already done some of the work on that
task, the start date MUST reflect the date the work was actually done for
any of it to make sense and thus that can ONLY be a date sometime before
today.

There are 3 starts to be look at - Start (ie, the planned start), Actual
Start, and Baseline Start. Before work is done, Actual Start = NA and
Baseline Start=Start. After some work has been done, Baseline
Start=originally scheduled date and Start=Actual Start.

 

[Peter Rooney]

Steve,

Eek! And to think that I thought thet the only things I didn't understand
were the things I'd put in my original message!

The tasks you mention were SCHEDULED for completion in mid-May, but because
of some useful copies and pastes, they've been completed ahead of schedule.

I sometimes wish it was easier to record actual start and actual finish in
Project without it overwriting the planned dates - still, you can't have
everything, can you?

I'm going to take a long hard look at your comments and try to ensure that
I'm using Project correcttly, because at the moment, I suspect that this
isn't strictly the case.

Thank you for taking the time to look at my question.

Regards

Pete

 

[Steve House [Project MVP]]

Actually you have your wish. Remember baselines are there to store your
original planned dates for future reference. The schedule (the plain Start
date column) shows projected dates for things in the future, planned dates
for things in the past that haven't been done yet (ie, are late), and actual
history for things that *have* been done. Before first posting any actuals
you save a baseline and that merely copies the plan as it sits over into a
set of fields that don't change unless you explicitly overwrite them with a
new baseline. When you view the Tracking table, entering the date work was
actually first done on a task in the Actual Start column does trigger the
Start column of the plain task table to change to the same date but the
baseline field does NOT change and continues to show the original plan so
you always know where you intended to be versus where you are.

So let's say one day's work was done last week on your 24 May task, jumping
the gun. Before posting it the plan shows Start of 24 May, Actual Start of
NA, Baseline start of 24 May, Duration 2 days, Actual Duration zero and
Remaining Duration zero. Someone was able to do some of the work last
Wednesday. After posting it the file should show Start of 04 May, Actual
Start of 04 May, Baseline Start of 24 May, Duration 2 days, % Complete 50%,
Actual Duration 1 day, Remaining Duration 1 day and a gap between last
Wednesday and 24 May where it is scheduled to resume.

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

 

[Peter Rooney]

Steve,

Apologies for not getting back to you sooner - I've been trying to test this
out all day, but, people keep giving me work to do - it's SO unreasonable!
Anyway, I'll give it a go tomorrow now, but I just wanted to say thanks for
taking so much trouble in trying to address my query - I really do appreciate
it. I'll let you know how I get on!

Regards

pete