How is the “activity time” estimates done?

Estimating activity time is a crucial aspect of project management, and there are several methods commonly used to accomplish this. Here’s how you might answer this question:

1. Expert Judgment: This involves consulting with individuals or teams who have experience in similar activities or projects. Their insights and expertise can provide valuable input for estimating activity times based on past experiences and knowledge.
2. Analogous Estimating: This method relies on historical data from similar projects as a basis for estimating the duration of current activities. It’s particularly useful when detailed information about the current project is limited.
3. Parametric Estimating: Here, the duration of an activity is estimated based on a statistical relationship between the quantity of work involved and the time required to complete it. This method is more precise than analogous estimating and is often used in repetitive or routine activities.
4. Three-Point Estimating: Also known as PERT (Program Evaluation and Review Technique), this method involves estimating three scenarios for each activity: the optimistic, pessimistic, and most likely durations. These estimates are then used to calculate a weighted average, providing a more realistic estimate that considers uncertainties and risks.
5. Delphi Technique: This approach involves gathering input from a panel of experts anonymously. The experts provide estimates independently, and the facilitator aggregates and shares the results. This process continues iteratively until a consensus is reached, helping to mitigate biases and uncertainties.
6. Reserve Analysis: Project managers may allocate contingency reserves to account for uncertainties and risks associated with activity durations. This involves setting aside additional time or resources to accommodate potential delays or setbacks.
7. Historical Information: Project managers may refer to past project data and performance metrics to inform their estimates. Analyzing historical trends can provide valuable insights into potential risks and opportunities for improvement.
8. Software Tools: Various project management software tools offer features for estimating activity durations, often utilizing algorithms and historical data to generate forecasts. These tools can streamline the estimation process and provide a standardized approach within an organization.

In practice, project managers often use a combination of these methods, tailoring their approach to the specific characteristics and requirements of the project at hand. It’s essential to consider factors such as the level of uncertainty, the complexity of activities, available resources, and the expertise of the project team when determining the most appropriate estimation technique. Additionally, revisiting and updating estimates throughout the project lifecycle is crucial to account for changes in scope, resources, and external factors that may impact activity durations.