Introduction to Primavera P6 Top-Down Estimation
Primavera P6 contains a unique feature that allows the user to break down budgets into dispersed components by WBS and tasks throughout the project schedule. Projects will be allocated for a specific budget, and with this assigned cost, the Primavera P6 user will need to distribute the costs throughout the project schedule to specific tasks. Primavera P6’s top-down estimation feature helps the user quickly assign the budget for labor and non-labor based on weights per WBS and task. This article addresses how to use the Primavera P6 top-down estimation feature, which can be particularly useful for lump sum or fixed-price projects.
Using the Primavera P6 Top-Down Estimation Feature for Your Project Schedules
Take note that the Primavera P6 top-down estimation feature can be used whether or not the project schedule already contains hours or units. If the project schedule already contains hours, these will be reallocated based on the assigned weights per task.
We will start with a snapshot of a sample Primavera P6 schedule. The default setting is a weight of 1.0 for each task, and take note that the milestone tasks (zero duration activities) do not contain a weight since budgets are never assigned to milestones:
To use the Primavera P6 top-down estimation feature, go to the WBS structure in the open project schedule and click on the weight values under the “Est Weight” column and assign the desired weightings to each WBS:
If the Est Weight column does not show up in the default WBS tab, right-click in the WBS section and select “Columns” and then “Customize…”:
When the dialog box opens, select “Est Weight” under the General category and use the right arrow button in the center of the dialog box to move the selection over to the Selected Options section:
You can enter different weight values for each WBS:
Next, go to the Primavera P6 schedule view and update the weights for each task if necessary. Take note that any updates to the weights to the tasks in the schedule will also result in those updates to the WBS structure on the previous tab:
Next, go to the Tools tab and select “Top Down Estimation…” from the pull-down menu:
The Top-Down estimation dialog box will display the current units in the open project. Enter the updated total estimated units that you want to distribute throughout the project schedule:
When you receive the dialog box confirming your action, select “Yes”:
Then click “OK”:
Close the dialog box and you will be able to see how Primavera P6 used the estimated weights to distribute the new budgeted units throughout the project schedule. This snapshot is the budget before using the top-down estimation feature in Primavera P6:
This snapshot is the view after using the Primavera P6 top-down estimation feature. Notice the increase in the units based on the increased budget allocation and weightings per task:
Additional Primavera P6 Top-Down Estimation Features
Primavera P6 also allows you to assign a top-down estimation to a particular resource. To do this, simply highlight and select the task you are interested in and add a resource or create a new resource and assign it to a task:
Next, go to the top-down estimation feature as before and this time use the ellipsis next to the Resource option to select the resource that is assigned to the task in the step above. Populate the Estimated Units box and select “Apply”:
You can see where Primavera P6 assigned the 100 units to the task that was highlighted:
You can also select the “Save As…” button to save a copy of the estimate to use for future projects.
Conclusion:
Primavera P6 top-down estimation is a quick and efficient way to disperse a budget throughout a project schedule. This allows users to have flexibility in assigning weights and making the budget and unit allocation relatively fast and simple.
