Predicting vs. Forecasting

QUESTION (from LinkedIn): Forecasting the same as prediction? Which one is more realistic and easier to do?

ANSWER: Forecasting is different from predicting. Predicting is much easier but far less accurate.

Predicting is when you start making guesses about things. For example, you predict that laying sheet-rock will take 45 hours to do and you guess that it will be done in 2 weeks.

Forecasting, on the other hand, is when you take information from past jobs and apply it to a new job. For example, if you have seen that laying the sheet-rock for a 3,000 sq ft space takes 65 hours and it usually done in 4 weeks then the next time you have to quote out the same job you’ll be able to forecast how much its going to cost and how long it will really take i.e. when it will really be done after work starts on it.

The big difference is predicting is based on your best guess from experience. Forecasting is based on data you’ve actually recorded and tracked from previous jobs.

As it relates to Vertabase project management software, predicting is when you first enter in your best guess of estimated hours on a task and your estimated start and end dates for that task. Forecasting is when those estimated hours are based on actual hours tracked on those type of tasks and actual duration (the amount of time between the start date and actual end date) of that type of task. All that data is tracked automatically in the project management software and easy to report on – making forecasting a snap (and far more accurate than predicting).

4 Responses to “Predicting vs. Forecasting”

  1. pmhut

    How does the logic works to forecast tasks? and will the system do it automatically for you?

    PS: I think literally though they do mean the same thing.

  2. Mark Phillips

    The general idea is that having data can help you make a more informed plan rather than relying on your own perceptions of how projects have played out in the past.

    Literally, prediction has a connotation of prophesy or soothesaying, while forecasting has a connotation of calculation and modeling.