COMMON MISSOUTS WITH HISTORY BASED ESTIMATION - FORECASTING ELEMINATES ERRORS

Common Missouts in History based Estimation - In case of similar size projects, Managers  tend to apply the estimates of old project for the new one with adjustments up  or down depending upon the similarity of projects.

Evaluation of certain KEY VARIABLES which affect historical and current estimates are missed which results in IN ACCURATE ESTIMATES / UN REALISTIC PROJECT DURATION .  These Key Variables are

1. Resources and Technology, 2.Difference in Experience and Skills, 3. Morale 4. Time of Year and Complexity.

These  are not the exhaustive list of Variables, with more variables estimation accuracy is increased. 

This becomes the Key difference between ANALOGOUS ESTIMATION AND FORECASTING ESTIMATION TECHNIQUE whic is dealt below.

Similar to Analogous Estimation, Forecasting requires historical data and documenting disparity between projects

Forecasting is more detailed in comparison with Analogous Estimation Technique.

With Analogous Estimation - the estimates are adjusted up or down depending upon the similarity of projects.

Forecasting evaluates several variables that can affect historical values and current estimate

  1. Resources and Technology -  Deals with Resources and Technology Differences between CURRENT AND PAST  projects

                                                     You may not have Same resources and Technology that were used in Historical Project

                                                      or    You may have more and Better Resources and Technology.

2.  Difference in Experience and Skills.

                                                     If the  Team members planned for current project are Skilled More than ones who worked

                                                       in  Past Projects they might not need more time, training  or expend more resources for

                                                      the the project  . If team members planned do not have enough expertise, training plans

                                                       should be in place, this adds to overall project duration and cost

3. Morale -  Team with High Morale will be more productive with Creative Solutions. Team with Low Morale may even sabotage a project.

4. Time of the Year -  Time of the Year needs comparison between Historixal and current project. Example if the project requires digging a foundation , you wouldnt like to dig it during Rainy season or when the ground is frozen. Also the holidays that come during the period should be considered as people may go off in vacation.

5. Complexity - Complexity between historical and current project should be considered. As per PMI complexity mean No. of Concurrent Activities performed in a given time frame. Although the concurrent activities reduces project duration  but thera are risks associated to it. For example  If Concurrent activities use same Skilled Resources and if there is a Resource shortfall, how could we compensate ?