Using the elemental estimate you created in 7T, you will now determine an estimate of the actual costs of the work packages (and through a “roll-up” summation calculation, the overall project). These revised structures, and updated values, help the project team develop the full project estimate.
• Multiply the cost of each resource by its own unit price to determine the cost of each resource for each WBS element.
o Determine the total amount of resources, on a resource-by-resource basis, that would be necessary for all WBS elements at the next-to-the-lowest level. Only the total effort needs to be summarized to the mid-level elements for each resource, and not the intensity. o Repeat the process until you arrive at total resource expenditure, resource by resource, for the project. Remember that each higher-level element requires no new resources, only sums of its lower level elements, which are considered to be the “children” of that specific element.
o Conduct the same roll-up for the cost of each WBS element. Calculate the cost of each WBS element at the lowest level and then roll the costs up, level by level, to arrive at the total cost of the project (add up all the costs for each work package in a WBS deliverable; then add up all the deliverable sums for a total project estimate…this is the “roll-up”). o Based on resource expenditures or cost, calculate a percentage for each of the main deliverables (level-1 items) of the WBS. They should add up to 100 percent.
Remember, in the real world, your sponsor has probably given you a budget for the project (a “top down” budget). Using your bottom up estimate, you as the project team now have an idea as to whether or not you are going to be within the given budget, and can adjust accordingly.
• If you found that the cost was not within budget, the elemental estimates can be fine-tuned to enhance your plans. You would continue fine tuning the estimates of the lowest level items until you obtain what you believe is a reasonable tournament estimate.
o You would NOT change an elemental estimate from what you believe is the correct estimate.
o Additionally, you cannot change the estimated values for the items that are “parents” of lower-level (child) items. The estimate values for these intermediate-level elements result from summing child elements, and not from input.
