Knowing how to estimate the resources required to carry out a project is never the simplest of tasks.
Resources are people, equipment, places, money or anything else a project needs to be executed.
As a result, resources must be allocated for each activity on the to-do list.
Before you can assign resources to the project, however, you need to know their availability.
Some resources need to be scheduled in advance and may only be available at certain times or times – for example, a meeting room or a rented office.
The objective of the resource estimate is to allocate the necessary resources to each activity on the list.
There are five tools and techniques for estimating activity resources:
- The judgement of experts: this means involving experts who have already performed this type of work before and obtaining opinions on what resources are needed.
- Alternative analysis: this means considering different options on how to allocate resources. This includes changing the number of resources and the type of resources used. Many times, there is more than one way to perform a task, and alternative analysis helps you decide between different possibilities.
- Published estimation data: something that project managers in many industries use to understand how many resources they need for a specific project. These are based on articles, research and studies that collect, analyze and publish data from other people and organizations’ projects.
- Project management software: these often feature functions designed to help project managers estimate resource needs and constraints and find the best combination for the project in question.
- The bottom-up estimate: this means splitting complex tasks into simpler tasks and processing the resources needed for each small step. The need or cost of the resources of the individual tasks is then added together to obtain a total estimate. The smaller and more detailed the task, the greater the accuracy of this technique.
In another article we already talked about project estimation techniques.
Estimation of activities’ duration
Once you have finished estimating resources per activity, you have everything you need to understand how long it will take to complete each activity.
Estimating the duration of a task means starting with information about that specific task and then working with the project team to develop a time estimate.
Most of the time you will start with a rough estimate and then refine it.
When you talk about estimating project time, you may have already heard of effort. If you’re interested in learning more about it, you can check this article about effort and duration.
Here are the five tools and techniques to create more accurate durability estimates:
- The evaluation of the experts that will come from the members of the project team who are familiar with the work that needs to be done.
- The equivalent estimate, i.e. when looking at similar activities from previous projects and how much time they took.
- Parametric Estimation, i.e. linking the project data into a formula that provides an estimation.
- The three-point estimate, i.e. when three numbers come up: a realistic estimate that is more likely to occur, an optimistic estimate that represents the best scenario and a pessimistic estimate that represents the worst scenario. The final estimate is the weighted average of the three.
- The Back-up Analysis, i.e. adding extra time to the program (called emergency reserve or buffer) to take account of additional risk.
Activity duration estimates are a quantitative measure usually expressed in hours, weeks, days or months.
Another thing to keep in mind when estimating activity duration is to determine the effort required.
Duration is the amount of time an activity takes, while effort is the total number of people-hours required.
If, for example, two people work a total of 6 hours (3 hours one and 3 hours the other) to complete an activity, the duration is six hours. However, if these two people worked the whole time (simultaneously, for 6 hours), the duration would be 12 hours.
Project planning and critical roadmap
The project program must be approved and signed by the stakeholders and functional managers.
This ensures that everyone is familiar with the program, including dates and resource commitments.
In addition, (written) confirmation will be required that resources will be available as indicated in the planning.
Once approved, the program will become the baseline for the rest of the project.
The progress of the project and the completion of activities will be monitored compared to project planning to determine if the project is running as planned.
A delay in any of the activities in the critical roadmap will delay the entire project.
Resource equalization is used to examine and resolve the unequal use of resources, usually related to people or equipment, over time.
During the execution of project planning, the project manager will attempt to plan certain activities simultaneously.
As the project progresses, however, there are situations where more resources – such as equipment or people – may be needed than are available and planned.
The project manager will attempt to schedule certain tasks at the same time as the project is progressing.
When using project software, resource equalization can take place automatically, allowing the software to calculate delays and automatically update tasks.
The project manager offers several tools for the development of good quantitative information, based on numbers and measurements, such as project schedules, financial and budget reports, risk analysis and objective monitoring.
This quantitative information is essential to understand the current status and trends of a project.
Likewise important is the development of qualitative information, such as judgement made by team members.
In conclusion, regardless of project size or budget, estimating activities can be a challenging task.
To create a feasible budget, the project manager needs to know their team, results, activities, and processes in detail.
In addition, he or she should feel comfortable asking the correct questions to stakeholders.