Changing work calendars in MS Project

Posted on 2005-04-25
Last Modified: 2013-11-15

my boss gave me a task to compress a project by 15%. I have tried and tried using adding resources to critical path activities but only get to 8%.

I realize I can achieve better results by simultaneously running the critical path work elements on 24 hour shifts. So if I have 6 workers right now on the task, I would like to work 18 workers, in three 8 hour shifts.

How do I do this, and is this feasible?

Question by:enzymemedia
    LVL 15

    Expert Comment

    If you are going to run 24 hour shifts....the easiest way to get your tasks on it is to use elapsed time for durations. Instead of 24h you would use 24eh to indicate elapsed time (on 24 hour clock). As far as setting up custom schedules this you can do from your resource sheet. 24shift is a default available base calendar. But you could also make 3 new calendars with the appropriate hours and assign each resource to a shift calendar. That is done in Tools...change working time and use the New button to define custom work schedules.

    As far as feasibility. I suppose that depends on your workforce. If compression is time only... even extending the workday a couple of hours could get you there.

    Author Comment

    Can you please give me a clearer outline for this... a little confused...

    LVL 4

    Assisted Solution

    It looks like you've fallen into a classic trap which is that you've tried to reflect resource constraints in your schedule linkages.  I recommend against this. Say you have 3 tasks which can all start at the same time except for the fact that you only have 1 resouce to work on them, DO NOT LINK THE TASKS TO EACH OTHER, just have them linked to their logical predecessor - it will first look like this...

    task                   Resource
    1       XXXXXXX  A
    2       XXXXXXX  A
    3       XXXXXXX  A

    And resource A will obviouly be overloaded - now go tools-level resources-level now and it will look like this

    task                                              Resource
    1       XXXXXXX                             A
    2                     XXXXXXX               A
    3                                   XXXXXX   A

    The beauty of this approach is that you can undo levelling and also substitute a resource and re-run levelling to get say this

    task                                Resource
    1       XXXXXXX               A
    2       XXXXXXX               B
    3                     XXXXXX   A

    To do the shift thing, I recommend that you set up the calendars as suggested by dbase118.  Make 3 calendars for shift A, B, and C and then assign each resource to their respective shift calendar.  remember that the base calendar for the proect will apply until you assign the resource and then the resource's base calendar will trump that of the project's base calendar.

    Another approach is to use overtime.  From the Gantt chart go Window-Split, R click the lower part of the screen and select Work.  For any task you select in the Gantt chart, you'll see the work that resources are assigned in the lower part.  However, here's where you can authorize overtime and Project will then schedule work to take place outside of the base calendar's working hours and bring the end date forward automatically.  Say you have a resource assigned to work 40hrs from Mon to Fri.  If you authorize 8 hours of overtime, the job can be done in 4 days now with the resource working 4 x 10 hour days.  Also this method is neat because, any overtime rates that you put in for the resource will calculate the higher cost of authorizing overtime work for you.  Note that in the example I gave, you are not authorizing an additional 8 hours of work, you are saying that 8 of the 40 can be done as overtime but it's still a 40 hour job.
    LVL 15

    Expert Comment

    I will try.

    If you would like to go to a 3 shift system. I would start by going to Tools menu and change working time. Once there click the new button and you will be able to define the normal working hours for that calendar. You will do this 3 times to define the three shifts. Once you have the three defines then you can go to the resource sheet and find the base calendar column. Now you assign each resource to a base calendar that matches thier shift.

    The other thing I mentioned is that when you work off a 24 hour schedule you can use elapsed time in your durations. Elapsed time simply means that the task is being worked continuously. For example lets say I was building a house and I poured a concrete foundation. The concrete must set for 48 hours.

    If I put a task in for "let concrete dry" and put a duration of 48 hours. Projects default schedule will translate that to 6 days. However 48 elapsed hours is calculated as 2 days

    Any better?


    Author Comment

    Is getting better, but all of your instructions are very hard to follow for me. If you can post this as a simple outline, I will verify and validate that it works for me. No offense but I have dyslexia and it is very hard to ready your instructions. Just a 1-2-3 format to would help alot. I believe from perusing what has already been presented here that all I am missing is a format that I personally can find functional... the ideas seem to make sense...

    LVL 15

    Accepted Solution

    1.) Go To Tools menu and choose change working time.
    2.) Click the New button at bottom of dialog box
    3.) Type in a new name (Shift 1, shift 2, etc) and choose copy of standard
    4.) On the calendar graphic click and drag from M (monday) to F (friday) to highlight all days.
    5.) On right side of dialog box, enter hours to match with shift you are defining
         For example 12:00pm to 4:00pm and then 5:00pm to 9:00 pm (2 4 hour segments...separated by one hour meal break)
    6.) click OK

    try that part first
    LVL 10

    Assisted Solution

    The scheduling mechanism that determines working time for resources and tasks is "Calenders". Calenders determine the standard working time and nonworking time, such as weekends and holidays, for the project. They are used to determine resource availability, how resources assigned to tasks are scheduled, and how tasks themselves are scheduled. Project and task calendars are used in scheduling tasks, and, if resources are assigned to tasks, resource calendars are used as well.

    If you change working or nonworking time on a resource calendar and the resource is assigned to a task, the task is scheduled during the working time on the resource calendar. To work with calendars, on the Tools menu, click Change Working Time.

    Adjust the time a work resource spends on a critical task by adjusting work hours, units, assignment start and finish date, and work contours. If several resources are assigned to a task, you can distribute work among them in different ways.

    Contour the amount of work assigned across a time period. Here is how:

    On the View menu, click Task Usage.
    Resources are grouped under the tasks they are assigned to.

    In the Task Name field, select a resource you want to adjust work amounts for across the time period. In the timephased portion of the view, change the individual work value (or hours) for the assigned resource. In the Work contour box, click a contour pattern. An indicator representing the contour pattern appears in the Indicators field next to the assigned resource.

    Also this form of collapsing schedule, that is, by adding more resources to the critical path usually adds to the project cost.


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