How Cobra Calculates Progress to Determine Earned Value
Cobra calculates earned value on each work package according to different principles.
These principles include:
- Cobra uses the specified progress technique only for work packages that are in progress. Any planned work package that has not yet started has no earned value. Any completed work package has an earned value that is exactly equal to its budget.
- Cobra uses the included budget class of the earned value class to determine what budget is used for earned value calculation.
- Cobra performs the earned value calculation on a cumulative basis, then subtracts any previously calculated earned value to produce the earned value of the current period. This avoids rounding errors and allows you to correct mistakes with a negative increment in the current period. Zero increments are not stored explicitly.
- Cobra calculates the earned value for Level of Effort (LOE) work packages based on the status period. If an LOE work package is open, the budget before the status date is earned.
An LOE work package should be opened on or before the baseline start date of the work package. If you open an LOE work package in a status period after the baseline start date, a cumulative-to-date earned value record is placed in the current period. Similarly, if you change the budget in a previous period, a correcting entry is placed in the current period. This ensures that the cumulative-to-date earned value equals the cumulative-to-date budget. There is an option in the advance calendar process to automatically open LOE work packages.
- Percent Complete resource assignment allows you to specify the percent complete individually for each resource assignment.
Avoid using this progress technique when apportionment assignments are used for the work package. The Apportioned progress technique at the work package level is used to calculate the earned value for resource assignments that were added using apportionment calculations.
- All other progress techniques derive a percent complete of the work package and calculate the earned value from the first result of each resource assignment.
For example, if the 50-50 progress technique is applied to a work package in progress, 50% of the budget for each resource assignment is earned. If the Units Complete progress technique is applied to a work package, Cobra calculates the percent complete of the work package by dividing the units completed by the units to do. Even weighted milestones are used to calculate the percent complete of the work package.
By default, the Budget method is selected. This means that Cobra applies the progress technique initially to the first result of the resource assignment. Cobra then calculates the remaining results from this amount. Thus, a resource assignment with the first result of Hours will have its earned value calculated first in hours. The value is then applied as a percentage across the derived costs defined in the resource.