Personnel RRS feed

  • Question

  • I have a task in my project to move 25000 ton of rip-rap, I can assign 1 to 10 dump trucks and a driver to each truck across multiple time periods. Each truck can move 25 tons in 40 minutes, can I set up Project to calculate the task completion based on the amount of material one truck or a combination trucks can move. The next step in the task is based on the completion of this task. My standard calendar is a 10 hour day, but I can assign overtime and run the trucks longer.
    Thursday, January 24, 2013 9:25 PM

All replies

  • R Bousley,

    This type of calculation is better suited to Excel but let's see what we can come up with for a Project scenario. First, Project creates a schedule using the work equation:

    Duration = Work/Units

    So for your example, let's tweak things a bit to fit your needs. The "work" content is 25000 tons. The units (trucks) work at a level of 37.5 tons/hour or 375 tons in a 10 hour day, and you have up to 10 trucks available. Shoehorning this into Project's work equation says that a "unit" is worth 375 tons/day, so an assignment of 375% will give the work equivalent of 1 truck in one 10 hour day. On the Resource Sheet, you would set the truck resource for a maximum units of 3750% (10 trucks at 375% each). Set the task type to fixed work, (since you have a fixed pile of rip-rap), and then assign the truck resource at 375% for 1 truck, 750% for two trucks and so forth. Given that you have defined a day as 10 hours under File/Options/Schedule/hours per day, it will take 1 truck 666.7 days to do the whole job. That value will appear in the Duration field.

    Hope this helps.

    Note: If someone else has a more elegant approach, please jump in. I realize the above approach may not be the most desirable but it's an attempt to fit a round peg in a square hole.


    Friday, January 25, 2013 2:38 AM