Engineers collaborating on a blueprint with holographic projections of project timelines.

Project Time Forecasting: How to Avoid Costly Delays

Nico Varela in Tech & Innovation September 2025 • 4 min read.

"Discover earned schedule and earned duration management techniques to improve project planning and keep your projects on track."

In project management, uncertainty and risk often lead to frustrating delays and budget overruns. To combat these issues, accurate project forecasting is essential. Effective project control relies on diligent monitoring of progress, allowing project managers to predict final outcomes and take corrective actions when necessary. Without reliable forecasting, projects can quickly spiral out of control, leading to missed deadlines and financial losses.

One well-known method for monitoring project progress and forecasting both costs and timelines is Earned Value Management (EVM). EVM offers performance metrics for assessing cost and schedule performance. However, traditional EVM primarily uses cost-based metrics, which can be less reliable for schedule performance, especially towards the end of a project. This limitation prompted the development of the earned schedule (ES) concept.

The earned schedule (ES) concept addresses the shortcomings of EVM by providing a way to manage project timelines more effectively. Project time management can be handled with the same methodologies as cost. But ES uses earned value as a proxy to get the duration, which means ES is still cost-based. Earned Duration Management (EDM) eliminates the drawback; EDM is a method developed to fix the problem. This article delves into how ES and EDM can enhance project time forecasting, helping you stay proactive and avoid costly delays.

What are Earned Schedule (ES) and Earned Duration Management (EDM)?

Engineers collaborating on a blueprint with holographic projections of project timelines.

Earned Schedule (ES) is an extension of Earned Value Management (EVM) that focuses on monitoring schedule progress in time units rather than monetary units. Since EVM key metrics are cost-based, ES was developed as a time unit extension. Earned Schedule indicates the time at which the current earned value was planned to be earned. By converting earned value into a time-based metric, ES provides a more intuitive and reliable way to track project timelines.

Earned Duration Management (EDM) builds upon the principles of EVM and ES but uses duration-based metrics to remove one of the ES perceived problems. Instead of relying on cost data, EDM uses measures the value of project activities in work periods. EDM focuses on time. This approach offers a more direct assessment of schedule performance, independent of cost fluctuations.

Here’s a breakdown of the key differences:

Metrics: ES uses cost-based metrics converted to time, while EDM uses duration-based metrics.
Focus: ES focuses on the time at which work was planned to be completed, whereas EDM focuses on the amount of work completed in terms of time.
Independence: EDM is independent of cost structures, providing a pure measure of schedule performance.

Both ES and EDM offer advantages over traditional EVM by providing more accurate and time-focused insights into project performance. By understanding these methods, project managers can make better decisions and keep their projects on track.

Making Time for Project Success

By using composite performance factors and understanding project characteristics, project managers can significantly improve the accuracy of their forecasts. Whether you choose to implement earned schedule or earned duration management, these techniques provide valuable insights for staying on track and achieving project success. Start exploring these methods today to transform your approach to project time forecasting and delay prevention. For more detailed strategies, delve into real-life project applications to improve results in project forecasting.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

Everything You Need To Know

What is the main drawback of using Earned Value Management (EVM) for schedule performance, and how does Earned Schedule (ES) address it?

The primary limitation of Earned Value Management (EVM) in schedule performance lies in its reliance on cost-based metrics. This can be less reliable, particularly as a project nears completion, because cost fluctuations may not accurately reflect schedule deviations. Earned Schedule (ES) addresses this by converting the cost-based metrics of EVM into time-based metrics. ES uses earned value as a proxy to get the duration, which offers a more intuitive and reliable way to track project timelines. However, ES still has a cost component.

How does Earned Duration Management (EDM) differ from Earned Schedule (ES), and what specific benefits does EDM offer?

Earned Duration Management (EDM) distinguishes itself from Earned Schedule (ES) by using duration-based metrics, whereas ES still relies on cost-based metrics converted to time. EDM measures the value of project activities in work periods and provides a more direct assessment of schedule performance, independent of cost fluctuations. This independence from cost structures is a key benefit of EDM, offering a more accurate and pure measure of schedule performance. The focus of EDM is on time, thus eliminating one of the ES perceived problems.

Why is accurate project forecasting essential, and what are the potential consequences of unreliable forecasting?

Accurate project forecasting is crucial in project management because it helps mitigate the uncertainty and risks that often lead to frustrating delays and budget overruns. Effective project control relies on diligent monitoring of progress, allowing project managers to predict final outcomes and take corrective actions. Unreliable forecasting can lead to missed deadlines and financial losses, potentially causing significant project failures and damaging stakeholder relationships.

Can you provide a practical example to illustrate how Earned Schedule (ES) or Earned Duration Management (EDM) can be used to improve project time forecasting?

While the text does not offer a specific practical example, the core principle involves using ES or EDM to monitor project progress in time units (ES) or duration-based metrics (EDM), rather than solely relying on cost data. For instance, if a project planned to complete a specific task in 10 days but the Earned Schedule (ES) analysis reveals that it is taking 12 days to reach the planned earned value, the project manager can see that the project is behind schedule. In EDM, the project manager can directly assess how much of the work is completed in terms of time (e.g., work periods), providing a more precise view of schedule performance and the time impact on the completion of the project. This early insight allows for proactive adjustments to resource allocation or schedule revisions to get the project back on track.

What are the key takeaways for project managers looking to implement Earned Schedule (ES) or Earned Duration Management (EDM) to enhance project success?

Project managers looking to implement Earned Schedule (ES) or Earned Duration Management (EDM) should focus on understanding the core differences: ES uses cost-based metrics converted to time, while EDM uses duration-based metrics. The key takeaway is that both methods provide valuable insights for staying on track and achieving project success by offering more accurate and time-focused insights into project performance than traditional Earned Value Management (EVM). ES offers a time-based extension to EVM, while EDM provides a more direct assessment of schedule performance independent of cost. Implementing these techniques requires a shift in mindset towards proactive monitoring and timely corrective actions, improving the overall project control.