As Project Managers we know that we have several methods to obtain the duration estimates for the activities of our project:
- Heuristics: these are methods based on guessing and applying the Rule of Thumb (this expression alludes to making rough estimates of measurements by using one’s thumb; an example of heuristic is the 80/20 rule).
- Analogous Estimating: based on similar projects, uses expert judgement and historical information to predict the future.
- Expert Judgement: we ask for estimates from people with deep knowledge on the matter. Usually this is an One-Point Estimate method, where each estimator submits one estimate per activity where he/she is an expert.
- Delphi Method: this is based on identifying 3 or 4 experts, without communication between them, in order to have independent estimates. We receive their estimates and if they are aproximate, we calculate the media. If estimates are very different, we resend them the considerations identified by the other, in order to receive a new estimate. If new estimates are close to each other, we will calculate the media, if not we will repeat the process.
- PERT (Program Evaluation and Review Technique) Analysis: this a Three-Point Estimates method, where we give an Optimistic (O), Pessimistic (P), and the Most likely (M) estimate for each activity. Then, we calculate the Expected Activity Duration (EAD) with the formula: EAD = (P+4M+O)/6. We can also obtain the +/- Standard Deviation (SD) of the activity, with the formula SD=(P-O)/6.
- Parametrics: these are methods based on formulas, built using historical information from previous projects. These try to identify the mathematical relation of two variables, applying Regression Analysis (Scatter Diagram). These methods also analyse the Learning Curve to calculate how fast we will increase the performance of repeated tasks in an activity as we go along.
Ok, this is how it usually works, but we don’t have to forget that we want to involve and empower our Project Team with the project in this critical phase. We will never demand from them to fulfill any End Date if they never were asked to establish that compromise.
On the other hand, if we, as Project Managers, compromise our teammates on the task of determining the duration of the activites and tasks of our project, we will have later good reasons to ask them to fulfill their work. More over, we will have an united team working together to achieve the same project goals as you.
Do you validate work estimates with your teammates?
Author: angelberniz (All Rights Reserved by the author).
Source: Original Text (based upon first hand knowledge).
Image courtesy of Ambro at FreeDigitalPhotos.net
Help us to improve it: how-to, discussion.
Join my community of 7 Million Unstoppable Learners who have enrolled in my FREE Online Courses and Certification Programs for Trainers, Experts & Professionals. Work with me, visit now: Courses10.com. Take Action. Get Results!