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What is EVM?

Earned Value Management is the gold standard for measuring project performance. It integrates scope, schedule, and cost into a single framework — giving you an objective view of where your project stands and where it is heading.

Instead of asking "How much have we spent?" and "Are we on time?" as separate questions, EVM combines both into a unified set of metrics. It answers the question every stakeholder actually cares about: Are we getting the value we planned for the money and time we have spent?

Nahla generates a complete EVM report from your uploaded P6 schedule (XER file). If your schedule is cost-loaded, the report is fully automatic. If not, you can upload a CSV of actual costs to get full EVM analysis.

The Key Metrics

Every EVM report is built on four foundational metrics. These are the raw numbers from which all performance indices and forecasts are derived.

BAC

Budget at Completion

The total planned budget for the entire project. Nahla reads this from the final point of the S-Curve at project end.

PV

Planned Value

The budgeted cost of work that was scheduled to be completed by the data date. Also known as BCWS.

EV

Earned Value

The budgeted cost of work actually performed by the data date. Measures the value of what has been accomplished. Also known as BCWP.

AC

Actual Cost

The real cost incurred for the work performed to date. This is the metric that can come from two different sources in Nahla. Also known as ACWP.

Where the numbers come from

BAC is taken from the project end point of the S-Curve (total budget). PV, EV, and AC are taken at the data date — the status date of your schedule. This distinction matters: BAC is the full picture, while PV/EV/AC are snapshots of progress at a point in time.

Performance Indices

Raw numbers tell you what happened. Performance indices tell you what it means. These ratios convert your EVM data into actionable intelligence.

Cost Performance Index (CPI)

Formula

CPI = EV / AC

CPI measures cost efficiency. A CPI of 1.0 or above means you are getting at least a dollar of value for every dollar spent. A CPI of below 1.0 means you are spending more than planned to achieve the same work. For example, a CPI of 0.85 means you are only getting 85 cents of value per dollar spent.

Schedule Performance Index (SPI)

Formula

SPI = EV / PV

SPI measures schedule efficiency. An SPI of 1.0 or above means work is being completed at or ahead of the planned rate. An SPI of below 1.0 means the project is behind schedule in terms of value delivered.

Cost Variance and Schedule Variance

Formulas

CV = EV - AC (positive = under budget) SV = EV - PV (positive = ahead of schedule)

Variances give you the absolute dollar difference rather than a ratio. A CV of -$50,000 tells you more than a CPI of 0.95 when you need to know the actual budget impact.

The Performance Quadrant

Combining CPI and SPI places your project in one of four performance scenarios:

Scenario	CPI	SPI	Meaning
Ahead & Under Budget	CPI > 1.0	SPI > 1.0	Ideal. Delivering more value for less cost and ahead of schedule.
Ahead & Over Budget	CPI < 1.0	SPI > 1.0	Schedule is fine but spending too much. May be crashing the schedule.
Behind & Under Budget	CPI > 1.0	SPI < 1.0	Costs are controlled but work is behind. Resource allocation may need review.
Behind & Over Budget	CPI < 1.0	SPI < 1.0	Worst case. Both cost and schedule are deteriorating. Immediate action required.

Scenario

CPI

SPI

Meaning

Ahead & Under Budget

CPI > 1.0

SPI > 1.0

Ideal. Delivering more value for less cost and ahead of schedule.

Ahead & Over Budget

CPI < 1.0

SPI > 1.0

Schedule is fine but spending too much. May be crashing the schedule.

Behind & Under Budget

CPI > 1.0

SPI < 1.0

Costs are controlled but work is behind. Resource allocation may need review.

Behind & Over Budget

CPI < 1.0

SPI < 1.0

Worst case. Both cost and schedule are deteriorating. Immediate action required.

4 EAC Forecasting Methods

Estimate at Completion (EAC) predicts the total final cost of your project based on current performance. Different assumptions about the nature of the variances produce different forecasts. Nahla supports all four standard methods.

1 Typical

EAC = BAC / CPI

Assumes the current cost trend will continue for the remainder of the project. If you have been 10% over budget so far, you will finish 10% over budget. Use this when cost performance has been consistent and is unlikely to change.

2 Atypical

EAC = AC + (BAC - EV)

Assumes the cost variance was a one-time event that will not repeat. The remaining work will be completed at the originally budgeted rate. Use this when the overrun was caused by a known, isolated issue (e.g., a one-off equipment failure).

3 CPI-Based (Default)

EAC = AC + (BAC - EV) / CPI

The most commonly used method. Calculates remaining work adjusted by cost efficiency. This is Nahla's default and the standard recommended by PMI. It accounts for the actual spending rate when projecting remaining costs.

4 Combined (CPI x SPI)

EAC = AC + (BAC - EV) / (CPI × SPI)

Factors in both cost and schedule performance. Use this when schedule delays are expected to cause additional costs — for example, extended site overhead, prolonged equipment rental, or delayed resource releases.

How to select your EAC method

On the Dashboard, navigate to the Earned Value tab. The EAC method selector lets you switch between all four methods. Once selected, every metric, chart, and AI commentary on the page recalculates instantly. There is no need to re-upload or refresh — the recalculation happens live in your browser.

EVM Data Sources

New Feature

The EVM report now supports two distinct data sources for Actual Cost. You can toggle between them on the Dashboard to compare schedule-based costs with real financial data.

Actual Cost is the one EVM metric that often differs between the schedule and the accounting system. P6 tracks resource assignments and rates, but finance tracks invoices, timesheets, and purchase orders. These rarely match exactly. Nahla now lets you work with both.

Schedule S-Curve

Actual Cost is derived from P6 resource assignments in your XER file. This is the default when your schedule is cost-loaded. It represents the schedule's view of what has been spent, based on assigned resource rates and quantities.

CSV Actual Costs

Actual Cost is overridden with real cost data uploaded as a CSV via the Dashboard. This represents the finance team's view — invoiced amounts, actual labour hours at actual rates, and real procurement costs.

How to toggle

On the Dashboard, open the Earned Value tab. The EVM source toggle appears alongside the EAC method selector. Switch between "Schedule S-Curve" and "CSV Actual Costs" to see how the two sources affect your EVM metrics.

What changes when you toggle

Because Actual Cost is the variable that changes, only cost-dependent metrics are affected. Schedule metrics remain unchanged since they depend solely on Planned Value and Earned Value, both of which come from the schedule.

• AFFECTED AC (Actual Cost) — directly changed by the source selection
• AFFECTED CPI (EV / AC) — denominator changes
• AFFECTED CV (EV - AC) — AC changes
• AFFECTED EAC (all 4 methods) — AC and/or CPI changes
• AFFECTED VAC (BAC - EAC) — EAC changes
• AFFECTED TCPI ((BAC - EV) / (BAC - AC)) — AC changes
• UNAFFECTED SPI (EV / PV) — both values come from the schedule
• UNAFFECTED SV (EV - PV) — both values come from the schedule
• UNAFFECTED BAC — total budget is always from the schedule

Why both sources matter

Comparing the two sources reveals discrepancies between what the schedule assumes and what finance reports. A large gap between Schedule AC and CSV AC may indicate outdated resource rates in P6, unplanned expenditures, or scope changes that have not been reflected in the schedule. This comparison is a powerful quality check for both your schedule and your cost data.

AI-Powered Analysis

Raw metrics are valuable, but interpretation takes experience. Nahla's AI reads your EVM data and provides three layers of analysis with every report:

Observation

A factual summary of what the numbers show. The AI identifies which indices are above or below thresholds, highlights trends across reporting periods, and flags anomalies such as a sudden CPI drop.

Method Context

The AI explains why the selected EAC method matters for your specific situation. If you have chosen the Combined method (CPI x SPI), it will note that this assumes schedule delays are driving additional costs and explain when that assumption holds or breaks down.

Recommendation

Actionable guidance based on the data. This might include recommending a schedule recovery plan if SPI is trending downward, suggesting a cost audit if CPI has declined for three consecutive periods, or advising a change in EAC method if conditions have shifted.

Context-Aware Commentary

The AI commentary updates automatically when you change either the EAC method or the data source. Switch from Schedule S-Curve to CSV Actual Costs, and the observation, context, and recommendation will reflect the new AC values and their implications.

Reading Your EVM Report

Let us walk through a sample EVM report to see how all the pieces fit together.

Sample Project: Office Fitout — Data Date: 15 Jan 2026

Budget at Completion (BAC) $2,400,000

Planned Value (PV) $1,200,000

Earned Value (EV) $1,080,000

Actual Cost — Schedule $1,150,000

Actual Cost — CSV Override $1,220,000

SPI (EV / PV) 0.90

SV (EV - PV) -$120,000

Using Schedule S-Curve AC ($1,150,000)

CPI 0.94

CV -$70,000

EAC (CPI-Based) $2,553,191

Using CSV Actual Costs ($1,220,000)

CPI 0.89

CV -$140,000

EAC (CPI-Based) $2,703,371

Notice that SPI and SV remain the same regardless of the AC source — they depend only on PV and EV. But the CPI-based EAC differs by over $150,000 between the two sources. In this example, the finance data (CSV) reveals higher actual spending than the schedule assumes, which produces a more pessimistic forecast.

This is exactly the kind of insight the source toggle is designed to surface. If your schedule shows a CPI of 0.94 but finance shows 0.89, there is a conversation to be had about whether P6 resource rates are current and whether all costs are being captured in the schedule.

Get started

Upload your P6 schedule (XER file) to nahla.ai and navigate to the Dashboard Earned Value tab. If your schedule is cost-loaded, the EVM report generates automatically. To use real cost data, upload a CSV of actual costs from the same tab.