🚀 Overview: Resolving FTE Calculation Discrepancies in Project Resource Plans

In Microsoft Project Online and Project Server environments (2013, 2016, and 2019), IT Administrators may encounter a specific logic error where Full Time Equivalent (FTE) values do not calculate as expected within Resource Plans. This issue typically manifests when switching between different timescale granularities (e.g., moving from weeks to months) for resources whose Max Units are defined as 0 or 0%.

Resource Plans serve as a critical high-level forecasting tool for Resource Managers, allowing them to estimate labor requirements for projects that are in the pipeline but not yet fully staffed. When the underlying calculation logic fails due to specific configuration settings, it can lead to inaccurate capacity planning and skewed Portfolio Analysis results.

⚙️ Key Technical Details

The calculation failure is not random; it is a result of the interaction between global server settings and individual resource attributes.

• The Conflict: The issue is triggered when Server Settings > Additional Server Settings > Resource Plan Work Day is configured to use “Resource Base Calendars” while the specific resource has Max Units set to 0.
• Default Fallback Logic: Because Project cannot mathematically process a zero-value for availability when calculating requirements against a calendar, it ignores the intended 0% availability. Instead, the system defaults to a fallback calculation of 8 hours per day, 7 days a week.
• FTE vs. Hours: This discrepancy is most visible when viewing Work Units as FTE. A resource with zero availability should theoretically yield zero FTE, but due to the fallback logic, the system generates unexpected numbers based on the 56-hour “default” week.

🛡️ Resolution and Workarounds

Administrators can resolve this behavior using one of the following two strategies:

• Strategy 1: Modify Work Day Settings — Change the Resource Plan Work Day setting to “Hours per Day”. This allows users to manually define the exact hour requirement for a resource within a specific period, bypassing the automated calendar/Max Unit calculation.
• Strategy 2: Adjust Resource Capacity — Update the resource’s Max Units to a value greater than 0%.
  • It is highly recommended to use 100% (1.0 FTE) for simplicity.
  • Note: If you use a higher value, such as 500% (representing 5 resources), you must enter FTE requirements as fractions of that total. For instance, requiring one person would necessitate entering 0.2 FTE.

📅 Best Practices for Resource Planning

• Initial Alignment: Always align the Resource Plan date range with the start of the project or the start of a major timescale period (e.g., the first day of the month). Entering data in the middle of a period can cause FTE distortions.
• Updating Resources: If you must change a resource’s Max Units after a plan is active, the most reliable method is to remove the resource, rebuild the team, and then refresh the Resource Plan.
• Granularity Management: For the most accurate “roll-up” when switching timescales, enter data at the Day level and skip weekends. Entering data at higher granularities (like Months) may cause the system to spread the work across non-working days.

⚠️ Impact

Failure to address these calculation errors has a significant downstream effect on organizational decision-making:

• Portfolio Analysis: Resource Plans are a primary data source for Portfolio Analysis. Inaccurate FTE counts will lead to incorrect “Resource Constraint Analysis,” potentially causing the organization to over-hire or reject projects based on false capacity shortages.
• Generic Resource Limitations: While using Generic Resources (set to 100% Max Units) is a recommended workaround for planning, be aware that Generic Resources are excluded from the “Resource Requirements availability view” in Portfolio Analysis. Only named resources mapped to specific roles/skills are aggregated in that view.
• Administrative Overhead: If not corrected at the server level, Business Analysts may feel compelled to perform manual offline calculations, leading to a “shadow” reporting system that contradicts the data in Project Server/Online.

Official Source: Read the full article on Microsoft.com