resource cost calculation issue RRS feed

  • Question

  • Hi,

    I have a resource management challenge- 
    In my project there is a machine which is allocated to a task.
    Say I want to define that while the project daily work duration is 9 hours, the specific task daily duration will be only 3 hours. In other words, the machine as resource will be allocated to the task only 3 hours a day. I do so by defining a specific calendar to the task. the machine allocation cost should be calculated accordingly: 
    3 hours/day x  cost/hour = total daily cost.

    Issue is, I get the project daily duration in the calculation:
    9 hours/day x cost /hour

    question is, why even though I did define a specific calendar to the task, MS project still calculates the total machine allocation to task cost according to the project calendar daily duration definition?

    Monday, April 22, 2019 2:32 PM


  • I have been watching this discussion. Have you tried the task usage view or the resource usage view? You can edit the distribution of work.
    • Marked as answer by inbalsv Tuesday, April 30, 2019 7:27 AM
    Tuesday, April 30, 2019 6:58 AM

All replies

  • inbalsv,

    You're first mistake is setting the Task calendar for 3 hr per day. You said the daily work schedule is a 9h day so that's what the Project calendar should reflect and that's what the tasks should be (i.e. Task calendar ? "none"). What you really have is a resource that only works 3 hrs per day, so assign the custom 3 hr/day calendar as the Base calendar for the resource.

    I've created an example 1 day task to which I've assigned the machine resource. This is what I get. Note the cost represents only the 3 hrs of resource time.

    Hope this helps.


    Monday, April 22, 2019 3:50 PM
  • Hi John,

    first of all thanks, 

    The problem is that i have some resources and tasks ,each resource is assigned to a different task and each task has a different duration.



    Tuesday, April 23, 2019 9:29 AM
  • inbal,

    Okay, so what's the issue? A "normal" project plan has multiple tasks and most often, multiple resources. Task durations will vary depending on the scope of the effort to be performed and may have one or more resources assigned. Nothing unusual in that.

    Your original post gave a specific scenario and I responded with one way to approach it. If that is not adequate, then you need to give us a much better description of what you are trying to do and what you hope to achieve. Only then can we give you suggestions on how to get there.


    Tuesday, April 23, 2019 3:05 PM
  • John,

    Lets say that I want to set 2 tasks. The duration of the first task is 3 hours and the second is 10 hours,each task has different resources(machines). Working day lasts 9 hours (according to the project calendar).

    I set a calendar to task 1 that says that working time is 3 hours per day and another calendar for task 2 that says that working time is 10 hours per day. Each machine costs 10 $ per hour. I want MS project to calculate the cost of using the resources according to the duration of the tasks.

    For example if one machine is allocated to the first task that lasts 3 hours and the same machine is allocated to the second task that lasts 10 hours the total cost should show :

    machine 1- cost: 30 $
    machine 2- cost: 100 $

    Instead, in the current situation, MS project calculates the cost according to the project calendar (9 hours per day ) and shows:

    machine 1- cost: 90 $
    machine 2- cost: 90 $

    Thanks, Inbal

    • Edited by inbalsv Sunday, April 28, 2019 9:29 AM
    Sunday, April 28, 2019 8:20 AM
  • inbalsv,

    You seem to have ignored what I told you in my initial response. For this scenario do NOT use a task calendar.

    Okay, here's how it lays out. This is one example of a custom project calendar for a 9h day.

    And this is the definition for the machine resource. Note that it's base calendar is the 9h/day project calendar

    You state that the first task has a duration of 3 hours and the second task has a duration of 10 hours. Since the same machine is assigned to both tasks, the tasks cannot be performed in parallel. The single machine resource is assigned at 100% to each of the tasks, which means the work time will equal the duration time. As can be seen, the costs are $30 for the first task and $100 for the second task, just what you want.

    Make sense?


    Sunday, April 28, 2019 4:20 PM
  • Hi John,

    I'm sorry but No.

    According to your answer the machine will work only 3 hours on the 22/4/19, but what i meant is that the machine will work for example for a week on task 1 and in each day she will work 3 hours.

    Thanks, Inbal 
    • Edited by inbalsv Tuesday, April 30, 2019 4:43 AM
    Tuesday, April 30, 2019 4:42 AM
  • I have been watching this discussion. Have you tried the task usage view or the resource usage view? You can edit the distribution of work.
    • Marked as answer by inbalsv Tuesday, April 30, 2019 7:27 AM
    Tuesday, April 30, 2019 6:58 AM
  • Thanks!

    Its working now. 


    Tuesday, April 30, 2019 7:31 AM
  • inbalsv,

    The solution I presented was based on the scenario you presented. Had you given me better information, we could have gotten to a solution sooner. Nonetheless, I'm glad Trevor was able to step in and give you what you needed.


    Tuesday, April 30, 2019 2:41 PM
  • Inbal,

    Ultimately, introducing multiple calendars (whether task or resource) can really confuse the meaning of "day," and I suspect this is at the root of your issue/problem/question.

    You have separately defined 1 "day" = 9 hours (540 minutes) for this project.  Regardless of the task or resource (or project) calendar applied, this is the definition of "day."

    Since each machine costs $10 per hour to run, $90 is the cost of 9 hours of work - i.e. the cost of 1 "day" of work.

    If Machine 1 (on a 5dx3h calendar) is the only resource assigned to Task 1 - which starts on Monday and finishes on Friday - then the duration of Task 1 is 5 x 3 = 15 hours.  That's 1.67 "days", not 5 days as you might expect.  Dividing the cost ($150) by the duration (1.67 days) yields $90 per "day".  There can be no other answer.

    Perhaps displaying the Resource Usage or Task Usage view allowed you see this  In any case, you've suggested nothing that implies the need to directly edit any usage.  

    Good luck, tom

    Tuesday, April 30, 2019 4:18 PM