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Assigning WBS Category Values
For more information about defining a WBS category and values, see “Defining Administrative Preferences and Categories” on page 29.
Depending on your security profile, you can define a custom category and category values for WBS elements. This category and its values are not project-specific; you can assign category values to all WBS elements in the EPS, which allows you to customize the module to reflect your organization’s terminology and unique requirements. This category and its values also enables you to group, sort, and filter WBS elements.
Establish a custom category and its values using the Admin Categories dialog box. The Admin Categories dialog box appears when you choose Admin, Admin Categories.
Assign a WBS category value Choose Project, WBS. Add the WBS category as a column by clicking the Display Options bar and choosing Columns, Customize. Select the WBS category name under General in the Available Options area, then click the right arrow button to move it to the Selected Options column; click OK. Select the WBS element to which you want to assign a category value, then click the Browse button in the WBS category column.
Select the value to assign to the WBS element, click the Select button, then click the Close button.
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Defining Earned Value Settings for Specific WBS Elements
To define default earned value settings for all WBS elements, choose Admin, Admin Preferences, then click the Earned Value tab.
Earned value is a technique for measuring project performance according to both project costs and the schedule. This technique compares the budgeted cost of the work to the actual cost. While earned value analyses are typically performed for WBS elements, you can also perform an earned value analysis for activities and groups of activities.
Use the Earned Value tab in Work Breakdown Structure Details to specify settings for calculating the selected WBS element’s earned value. Earned Value cost is the portion of the budgeted total cost of the activity that is actually completed as of the project data date; it is calculated as
Earned Value = Budget At Completion (BAC) x Performance % Complete
The method for calculating the performance percent complete depends on the earned-value technique selected for the activity’s WBS.
Define earned value settings for a specific WBS element
Display Work Breakdown Structure Details by clicking the Display Options bar and choosing Show on Bottom, WBS Details. Select the WBS element whose earned value settings you want to define, then click the Earned Value tab.
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In the Technique for Computing Performance Percent Complete area, choose the completion percentage method you want to use when calculating an activity’s earned value:
■Activity Percent Complete: Calculates earned value according to current activity completion percentages and the percent complete type selected on the General tab of Activity Details. Mark Use Resource Curves / Future Period Buckets if you want to override the Activity Percent Complete type for activities that have a resource curve assigned to at least one of the resource assignments, or for activities that have assignments with manually-defined future period bucket values. If a curve is assigned, Units Percent Complete is always multiplied by the Budget at Completion to calculate Earned Value.
■WBS Milestones Percent Complete: Calculates earned value according to completion of the WBS element’s weighted milestones, rather than the completion percentages of the element’s activities.
■0/100 Percent Complete: Calculates earned value as 100 percent only after the activity ends. Until the activity is complete, the activity’s earned value is zero percent.
■50/50 Percent Complete: Calculates earned value as 50 percent after the activity starts and until the activity ends. After the activity ends, the activity’s earned value is 100 percent.
■Custom Percent Complete: Calculates earned value as a percentage you specify. This percentage applies after the activity starts and until the activity ends. After the activity ends, the activity’s earned value is 100 percent.
In the Technique for Computing ETC area, choose the method you want to use when calculating an activity’s estimate to complete (ETC) value:
■ETC = Remaining Cost for Activity: Calculates ETC values as the remaining cost to complete an activity (ETC = remaining duration of activity * applicable resource rates).
■PF = 1: Calculates ETC values as Budget At Completion (BAC) less Earned Value Cost. This method yields an optimistic result.
■PF = 1/CPI: Calculates ETC values according to a Performance Factor (PF) of 1 divided by the Cost Performance Index (CPI).This method yields the most likely result.
■PF = 1/(CPI*SPI): Calculates ETC values according to a PF of 1 divided by the product of the CPI and Schedule Performance Index (SPI). This method yields a pessimistic result.
■PF =: Calculates ETC values according to a PF you specify.
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Assigning Estimation Weights to WBS Elements
For information about using Top-down Estimation, see “Performing Top-down Estimation” on page 261.
You can assign estimation weights to work breakdown structure (WBS) elements and activities to perform Top-down estimation. You can assign estimation weights directly in the Project Management module or import them from the Methodology Management module using Project Architect.
The Project Management module uses the estimation weights to calculate the number of units that each WBS element receives in relation to its lower-level elements in the WBS hierarchy. For example, if 1,000 days of labor are applied top down to three WBS elements with estimation weights of 30, 30, and 40, then each WBS element receives 300 days, 300 days, and 400 days, respectively. Top-down estimation weights are relative values between elements in the WBS hierarchy; the absolute values of the estimation weights have no meaning.
Top-down estimation uses the WBS Estimated Weight field to determine how to “push down” the units within each branch of the WBS. The algorithm is:
WBS 1.1 Weight
WBS 1.1 Units = Sum of All WBS Weights at WBS Level x Est Units
where:
WBS 1.1 Weight = Weight of WBS 1.1
WBS 1.1 Units = Number of Units Allocated to WBS Element 1.1
Sum of All WBS Weights at WBS Level = Sum of Weight of All WBSs at Same Level of Hierarchy as WBS 1.1
Est Units = Number of Estimated Units Distributed Among All WBSs at WBS Level 1.N
For example, if you select a WBS with three, level-one WBS elements beneath it, and each of those elements has a weight of 1 with an estimate of 100 days, the module calculates each WBS as having 33.3 days, as follows:
1
Units = 1 + 1 + 1 x 100d = 33.3d
Alternatively, if the weights for each WBS element vary, such as 6 for one element and 2 each for the other two elements, the result is 60 days for the first element, and 20 days each for the other two elements:
6
Units = 6 + 2 + 2 x 100d=60d
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The algorithm continues to calculate any lower-level WBS elements in the WBS branch to distribute the units accordingly. This process continues until all WBS levels in the branch have been considered; it then continues with the next branch in the hierarchy. The module ignores any WBS element that does not have activity assignments when distributing units within a branch of the WBS.
If an activity has multiple resources assigned, each resource will be allocated remaining units in proportion to how many remaining units each resource previously was assigned for that activity. For example, if Resource 1 previously had six hours of remaining units on an activity with remaining units of five days, and Resource 2 previously had four hours of remaining units, Resource 1 will now have remaining units of three days (24 hours) and Resource 2 will have remaining units of two days (16 hours).
If an activity is completed, that activity is allocated zero remaining units. If all activities under a WBS are completed, zero units are distributed to that WBS.
Assign estimation weights to WBS elements Choose Project, WBS. Click the Display Options bar, then choose Columns, Customize. In the Est Weight column, enter the applicable weights for each element listed.
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You can also right-click to select the columns to display for entering data.
Type directly in the column field for the WBS element to enter its estimated weight.
Assign estimation weights to activities Choose Project, Activities. Click the Display Options bar, then choose Columns. Add the Est Weight column by selecting it in the Available Columns list and clicking the right arrow. Click OK. Enter the applicable weights in the Est Weight column for each activity listed.
Est Weight is located under the General listing.
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