Hi,
As I promised I am going to explain how to assign resources to the Task, and what happens when I add or remove additional resources to those tasks in MS PROJECT 2010. After that I will explain the MAGIC FORMULA. So, if you are interested, continue to reading!
OK! First I will make a Set up! I will add new column Work
Now I will add Two Tasks to the Project:
As you can see Work is 0 hours? Why? Because Work field is directly connected with Resources!
I will put two Resources two resources to the Project:
I will assign both, John and Mary to the Task 1:
As you can see I get 32 hours in the Work field! It is a Simple calculation: 2 days X 8 hours per day X 2 persons = 32 Hours! You may ask: “Where did this 8 hours per day comes from?”. From here:
and then:
O.K.! I will assign John and Mary to the Task 2, but in this case I will assign only 50% of Mary To the Task!
and I will get:
As you can see I get 36 hours in the Work field! It is a Simple calculation: For John: 3 days X 8 hours per day (100%) X 1 person = 24 Hours! For Mary: 3 days X 4 hours per day (50%) X 1 person = 12 Hours. So John + Mary = 24 + 12 = 36 hours.
I will do the Same thing for both Tasks, but I will assign John first, and then Mary!
John is here, now I will assign Mary, and I will get:
It seems that everything is same as in my first example. But, did you notice the little green triangle in the upper left corner of the Task 1? If you put mouse pointer near it you will get so called: Action Button!
You have three choices! And I will explain them! Basically you have to give MS PROJECT 2010 the answer on the question: “OK. First you have assign John. Now, you want Mary on the same Task! WHY? WHAT DO YOU WANT TO ACHIEVE? WHY DO YOU NEED MARY?” And, there are three answers:
“Increase total work because the task requires more person-hours. Keep duration constant”! That means that you need more WORKING HOURS, and you can see in a picture above that in the Work field is 32 hours instead of 16.
“Reduce duration so the task end sooner, but requires same amount of work (person-hours)”! If I choose that one, I will get:
In this case I said to the MS PROJECT 2010: Well, John had to work 16 hours. I added Mary to The Task because I want this 16 hours to be split between John and Mary. John will work 8 hours per day, and Mary too. Since I need 16 hours to finish the Task the Task will have only one day, instead of two!
Last answer is:
“Reduce the hours that resource work per day. Keep duration and work the same”! If I choose that one, I will get:
In this case I said to the MS PROJECT 2010: Well, John had to work 16 hours. I added Mary to The Task because I want this 16 hours to be split between John and Mary. John will work 4 hours per day, and Mary too. The duration will be the same!
You can see that in Task Usage View:
Is it complicated? Yes it is. But, once when you get the point it will be much easier to work with MS PROJECT 2010!
I will continue in my next post with adding and removing Resources to and from Tasks!
Regards,
Nenad Trajkovski 
Hi Nenad
Please, how can have in “work” field only the amount of hours of human resource ?
Thanks for your great post, Nenad Trajkovski. Keep up this good work :).
Thank you for your useful post. I have a question about the “Last answer” section of your post. If I set task type to “Fixed Work” or “Fixed Units”, when I pick “Reduce the hours that resource work per day…” MSP automatically reduces both the hours and percentages for each resource. However, when I set the task type to “Fixed Duration”, it reduces the hours for each resource but not the percentages corresponding to it. Does this result from a glitch or there is some logic behind this?
Regards
It is strange. I’m using MS PRoject 2016 Pro, and it reduces % as well
Very Usefull, Thank you very much
Thank you Paulo Costa
Hello, I need help. Is there an option in MSProject 2013 for multitasking.
I have 3 tasks and I have put the duration of each task. All the task should be done by the sam person. Is there somehow way to Ms Project autocalculate the unit usage?
What do you mean by “autocalculate unite usage”. Please give me more details about what do you want to achieve
YOU ARE A LIFE SAVER THANK YOU! XXXX
Nenad,
I think I figure it out from another of your posts. I’m basically selecting all the activities “John” is involved, clicking on “information” and selecting the “advanced” tab. MSP will allow me to change all (selected) tasks to “Effort Driven” – which makes them to have the behavior I wanted in my post above.
Thanks again for the extremely useful posts!
Nenad:
Thanks very much for the posting!
Do you know if there is any way of setting up a different default for this operation? More specifically, suppose that I have many tasks assigned to “John” and I want to reduce the project time by hiring another person (it could be “Mary”) to share the work with John. If I simply add Mary to all tasks, MSP would assume that all I want to increase the amount of work all those tasks need – which is not the reason I’m adding Mary.
Would I have to add Mary one task after another, changing each one individually to “Reduce duration so the task end sooner, but requires same amount of work (person-hours)”? Or is that a way of adding Mary to all tasks with the “Reduce duration…” option?
Very useful!! don’t you have videos to watch?
No, I do not 😦