Both parametric estimating and bottom-up estimating are cost estimation methods, but their approaches to estimating project costs differ.
To estimate the cost of a project based on parameters such as size, complexity, and effort, parametric estimating employs statistical relationships and historical data. This method is frequently used when detailed project information is unavailable, and it can be useful for projects that are similar to previous projects.
Bottom-up estimating, on the other hand, entails estimating the cost of individual project components and aggregating them to determine the total project cost. This method is frequently used when detailed project information is available and the project is made up of many small, distinct tasks.
Both methods have advantages and disadvantages, and which method is superior depends on the specific project and information available.
According to research, bottom-up estimating is generally considered to be more accurate than parametric estimating because it is based on detailed project information. Parametric estimating, on the other hand, can be faster and less expensive to perform than bottom-up estimating, making it a more appealing option for certain types of projects.
Finally, it is critical to consider the specific needs of your project and select the method that best meets those needs. It is also advantageous to combine both techniques to obtain a more accurate estimate.
