An office manager would be able to do a time series forecast of the quantity of her e-mails a year from now if she kept a daily record of her e-mail.

If the office manager kept a daily record of her past e-mails quantity, she can use that data to build a time series model and do a forecast for the future. Time series analysis is a statistical technique used to analyze and forecast data that changes over time. Therefore, if the data is well collected and analyzed, a time series forecast is possible.