Earned Value vs Earned Schedule — When the SV Lies, Reach for ES
Schedule Variance converges to zero as a late project completes. Earned Schedule corrects the well-known weakness of EVM for late projects.
Classic Earned Value Management has a well-documented blind spot. As a delayed project approaches completion, Schedule Variance (EV − PV) mathematically converges to zero — even though the project is finishing months late. The Schedule Performance Index returns to 1.0 right when the project is failing.
Earned Schedule
Walter Lipke's 2003 paper proposed translating the earned-value position back onto the planned-value time axis to derive Earned Schedule (ES). The metric is expressed in time units. SV(t) = ES − AT and SPI(t) = ES / AT remain meaningful through completion.
When to Switch
Run both. Use SPI for early-phase trends; switch the headline metric to SPI(t) once the project crosses 70% planned duration. Most modern reporting tools support both natively.
Frequently Asked Questions
What is "Earned Value vs Earned Schedule — When the SV Lies, Reach for ES" about?
Schedule Variance converges to zero as a late project completes. Earned Schedule corrects the well-known weakness of EVM for late projects. It sits within the Performance Measurement stream of PMMilestone Research & Insights and is written for practising project management and project controls professionals.Who is the intended audience for this Performance Measurement article?
Planning engineers, project controls engineers, cost engineers, project managers and owner-side advisors working on capital construction, infrastructure and power projects. The article assumes working familiarity with CPM scheduling, EVM and risk management.Who authored this research article?
Dr. Hassan Eliwa, PhD — Founder of PMMilestone.org, senior planning and project controls engineer with 17+ years of international field experience and a PhD from Massey University (New Zealand).Which calculators and templates pair with this article?
The EVM Calculator, SPI Calculator, CPI Calculator and Schedule Health Checker on PMMilestone.org cover the formulas referenced here. Companion templates (risk register, EVM workbook) are linked from the relevant sections.What is a common misconception this Performance Measurement article corrects?
That headline SPI and CPI numbers can be read at face value. On real performance measurement programmes, schedule performance must be assessed using Earned Schedule SPI(t) past ~70% progress, and CPI is only reliable after 15–20% physical progress. The article walks through how to apply these caveats in practice.Where can I find related research and definitions?
Use the PMMilestone Encyclopedia A–Z for canonical definitions of every term referenced in the article, and the Research Articles index for adjacent long-form pieces.What are Dr. Hassan Eliwa's research areas relevant to "Earned Value vs Earned Schedule — When the SV Lies, Reach for ES"?
Dr. Hassan Eliwa's published research areas — owner-side project controls maturity, forensic delay analysis, earned schedule reliability on long-duration projects, and quantitative schedule-risk modelling — frame the analysis here. The full author profile and publication list live on the author page.