Schedule forecasts are the estimates or predictions of conditions and events in the project’s future based on information and knowledge available at the time the schedule is calculated. In the project management, forecasts are updated and reissued based on work performance information provided as the project is executed. The information is based on the project management’s past performance and expected future performance, and includes earned value performance indicators that could impact the project in the future.

The schedule forecasts are derived from progress against the schedule baseline and computed time estimate to complete (ETC). This is typically expressed in terms of schedule variance (SV) and schedule performance index (SPI). For projects not using earned value management, variances against the planned finish dates and forecasts finish dates are provided. In project management, forecast may be used to determine if the project is still within defined tolerance ranges and identify any necessary change requests.

To calculate the schedule forecasts, a schedule model may require more than one project calendar to allow for different work periods for some activities. Control schedule is the process of monitoring the status of project activities comprising the inputs, tools and techniques and output. The schedule forecasts fall under output process.