Welcome to Part II of the Five Part Blog Series -- “Steps to Create an OUM Estimating Model”.
Creating an Estimate vs. Creating an Estimating Model
First, let’s establish the difference between an estimate and an estimating model. A one-time estimate based on one’s unique experience is NOT an estimating model. Rather, this is an experienced based estimate. Often this “experienced based estimate” resembles a Work-breakdown Structure (WBS) with number of hours or days filled in based on one’s experience with each task. Although this type of estimate is slightly better than arriving at a number solely based on the high level attributes of a similar project, an experienced-based estimate is highly dependent on the experience of the person or people completing the estimate.
The goal of an estimating model is to create a repeatable model that will provide an estimate that yields the same result for the same scope of work regardless of who completes the estimate. To accomplish this effectively, the experience of many must be incorporated into the model in such as way as that the internal thought process that one goes through to determine the effort for a particular task is decomposed into questions and answers that can be presented by the estimator model and consistent effort calculated based on the answers.
Sounds simple so far, right?? Before we discuss the steps on how to create an estimating model, join tomorrow’s blog as we distinguish between various types of estimating models commonly found.