Estimation of Resources: Identifying Resources and Computing their Quantities.
Estimation of resources is the process of identifying and computing the requirement for human, material, and equipment resources necessary to perform project tasks. This process would help in the proper distribution of the required resources for the achievement of project objectives. Different ways of estimating resources are:
1. Expert Judgment
This will use the insight of subject matter experts or even valuable and experienced people whose exposure and experiences are based on using similar projects. Their inputs would then come up with a reasonable estimate of the type and amount of resources involved.
Example:
It entails that the civil engineer estimates the number of workers, materials, and equipment needed in excavation, carpentry, etc. in a construction project.
2. Analogous Estimating:
Predict resource needs based on historical data from analogous projects. The present method assumes that projects having similar scope and complexity characteristics would also exhibit similar requirements for resources.
Example:
A project that would require three developers and one DBA in a previous project of the same size and complexity could ensure this for future projects.
3. Bottom-up Estimation:
The project is subdivided into small indications, and the required resource is calculated for each of them and added to obtain the total requirement.
Example:
A marketing campaign is split up into market research, content creation, and the design of graphics, to estimate resources, calculate hours of each task, and then just sum those estimates to arrive at total requirements.
Time Estimation:
Time estimation is very important for preparing the project schedule and defines how much time a specific activity will take. The methods are:
1. Expert Judgment
Seeking consultation with experienced people on a task’s complexity, its links, and risks before estimating task duration.
Example:
An experienced project manager in website development may guess such durations as wireframes, coding, and testing.
2. Historical Data Analysis
Finding Previous Data Measure out previous project information and establish any pattern and trend taking to perform a task-duration that would afterwards be the basis of current tasks.
Example:
If previous software projects took about three weeks to develop a certain module, this will give an informed guess of how long it might take to develop such a similar module.
3. Three-Point Estimation:
To account for all different scenarios, estimates for activity duration are derived under the optimistic, pessimistic, and most likely cases, and the figures are plugged into a weighted average formula.
Example:
For a task that involves estimating the optimism at 7 days, the most likely taking about 10 days, and the pessimistic of about 14 days, use:
(Optimistic + 4 × Most Likely + Pessimistic)
÷6 to evaluate the days to complete the task.
(Optimistic + 4 × Most Likely + Pessimistic)÷6 yields
(
7+
4×10+
14
)
÷
6
=
11
(7+4×10+14)÷6=11 days.
4. Parametric Estimation
Estimates in terms of statistical models from historical databases and available for parameters like size, and complexity.
Example:
In construction, pouring concrete may take place on a volumetric basis function on the headcount of labor and the efficiency rate of that workforce.
This means that these methods of estimating resources and times will go far in achieving effectiveness for project managers in resource allocation.
