• ### Question

• Please, could you help me to better understand the calculating methods of MS Project because I don't well understand MS Project behaviour: To explain my problem, here is my context :
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CONTEX
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Calendar : Std (08:00-12:00 / 13:00-17:00) assigned to all tasks
Auto schedule activated

Resource R1 :

• Calendar standard excepted for February 10 2014 with working time 08:00 - 12:00
• Capacity ___
For February 10, 2014 = 100%
For February 11 to 15, 2014 = 50%
• Cost rate___
for February 10 , 2014 Std rate 10€ and overtime rate 20€
for February 11, 2014 std rate 20€ overtime rate 40€

• Constraint Start not earlier than February 10, 2014 08:00
• finish date February 11,2014 17:00
• fixed Work = 15h

For the Gantt Chart, I display Resource usage view => 3 panels + 1 chart

• On the left detail part, I enter 7h on the overtime work field (after manual insert of this field)
• On the  right part of the resource usage view, I enter for :
February 10 , work 8 => overallocation automatically calculated  = 4 => Ok
February 11, work 7 =>  overallocation automatically calculated  = 3 => Ok

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PROBLEM
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But MS project calculates also overtime work, and I don't understand how because

• For February 10 , overtime work  = 3,28h
• For February 11, ovt work = 3,72
• Firstly, no way to change this repartition, automatically calculated. Impossible to type data on ovt work field
• Secondly, it's better to overload the ovt work of the Feb. 10 because this ovt rate is lower than the ovt rate of the Feb.11
• Finally the total calculated cost  by Project = €327,19 but according to my own calculation it should be egal to €334,40
Feb 10 = 4h std time x 10 std rate  + 3,28h ovt x 20 ovt rate = €105,60
Feb 11 = (4 x 20 ) + (3,72 x 40) = €228,80
Total cost = €334,40

Thanks a lot for your help

Tuesday, February 11, 2014 11:02 AM

### All replies

• Hmm.  That is not what I see:

Before assigning the overtime, the task duration expands to 1.88 days and the resource is overallocated on Feb 11 and Feb 12.  When you assign a resource, their assignment units is equal to the max units for the start of the task - in this case 100%.  For Feb 10, the resource is assigned 4 hours (due to non-working time) at 100%.  On Feb 11 the resource is assigned 8 hours due to 100% assignment units and on Feb 12, the resource is assigned 3 hours at 100% assignment units.

When I assign 7 hours of over time this is what I see:

Project splits the 7 hours of overtime over the two days - 3.5 hours each.

What version of Project (2010? 2013?) and what service pack?

Tuesday, February 11, 2014 3:12 PM
• Hi Julie

In my case, for Feb 11, capacity is only 50% for the resource => Only  4h working time

My question is also about ovt work field, is it possible to manually enter data in this field?

Why the MS Project total cost  = €327,19 while, according to my calculating, it should be = €334,40

Tuesday, February 11, 2014 9:45 PM
• No, you cannot manually enter Overtime work in the timescaled view of Task Usage or Resource Usage. Project will also not modify the amount of overtime based upon what is the most cost effective.  In my scenario, the overtime was split evenly based upon the assignment units of 100% for both days.

I am seeing what I consider an error in the assignment values that Project is using.  When I did your scenario test yesterday (Feb 10) the resource was assigned 4 hours of work but at 100% assignment value.  The 4 hours from the edited calendar but 100% because that was his/her max units.  The rest of the assignment was also at 100%, causing an overallocation.

However, today when I repeat the same scenario on a new file, I see the assignment units are incorrectly applied on Feb 10 - they are applied at 50% and the duration of the task blows up to 3.75 days.  It appears as though Project is assigning the resource at what ever their max units are as of the date of the assignment and not paying attention to the contoured availability.

Tuesday, February 11, 2014 11:17 PM
• Hi,

if I well understood, the working time of the resource assigned to a task is always its max capacity (units) regardless of its calendar constraints.Is it right?

What do you think about the repartition of the overtime work? Is it optimized?

Wednesday, February 12, 2014 9:03 AM
• The assignment and work for a resource is a combination of the max units and the calendar.  You have contoured your resource's max units but on Day 1 their max is 100%.  However, you have changed their calendar to only allow 4 hours of work (8-12).  So, the first day the assignment units is 100% - but only 4 hours of work.  The other days the resource should only be scheduled for 4 hours per day - due to the 50% assignment unit.

Project should assign the resource at the max units at the start of the task - creating an overallocation for the second and third day.

Regarding the OT work - no, it is not optimized.  Project split the 7 hours evenly.  Project subtracts the 7 hours of OT from the total 15 hours of work and divides the regular work to 4 hours on Monday (because of the calendar) and the remaining 4 on Tuesday.

Thursday, February 13, 2014 10:48 AM
• Hi Julie,

Does it means that cost is approximate when  I optimize the repartition of overtime work due to impossibility to enter manually overtime work into MS Project?

Thursday, February 13, 2014 4:06 PM
• I wouldn't say the cost is approximate.  Based upon what I see:

4 hours regular at \$10
3.5 OT at \$20

4 hours Regular at \$20
3.5 OT at \$40

The costs are correct - \$110 for day one \$220 for day two.

Thursday, February 13, 2014 8:36 PM
• Thanks a lot Julie

You are right, calculating is correct.

May I ask you to help me again about Completion percentage ?

My question is if the status date project > a Task finish date and I allocated a completion % < 100% =>? New finish date for the task?

I already posted this question on the forum but impossible to make a link

Friday, February 21, 2014 7:52 PM
• I see Dale has helped you out.

Friday, February 21, 2014 9:35 PM
• Hi Julie,

Could you help me about my question

Sorry for @ but I'm not allowed to enter hyperlinks (???)