Estimation by Analogy and Relative Sizing

Project Managers put a lot of time and effort to successfully deliver the project. What they need is a robust technique to estimate their project. In Project Management, Analogous and Relative-Size Estimation are popular techniques that allow us to predict the efforts required for the project tasks. Also, we can compare the efforts for new tasks with those of completed ones so that we can analyze our workflow efficiency and resource availability.

What is Project Estimation?

More than just determining the cost of a project, Project Estimation is a systematic process to predict and plan for the time, effort, and resources required to successfully deliver a project. This approach helps in strategic decision-making and enables teams to identify and resolve potential risks, uncertainties, and project complexities. So, Project Estimation allows us to predict project elements such as project duration, team size, and necessary tools to develop well-informed plans and make adjustments based on evolving requirements.

1. The information about the key project parameters like delivery timelines and resource needs helps the project professionals can proactively manage the project lifecycle.
2. This proactive approach to estimation plays an important role in preventing unplanned events, setbacks, and unexpected developments.
3. Effective Project Estimation acts as a baseline for successful project execution. Thus, helps the teams adapt to changing circumstances while maintaining overall project goals.

What is Estimation by Analogy?

Estimation by Analogy is a method that performs the comparison or analogy between the current or new tasks and similar tasks or activities from past projects. Analogous estimation draws the parallels between the cost figures and predictions of ongoing or upcoming tasks. It simply means that the parameters of current or upcoming tasks are compared with those of previous or completed tasks. Hence, analyzing historical data and project parameters becomes truly helpful for project professionals to estimate the efforts required for the current project.

1. The estimation process involves comparing the characteristics and requirements of current tasks with those of tasks that have been previously completed. This comparison helps in identifying similarities and patterns.
2. Past project parameters, such as costs, time, and resources, serve as the basis for estimation. By referencing historical data, project professionals can make informed predictions about the current project’s resource needs and potential challenges.

Advantages of Analogy Estimation

1. More accurate due to historical information: Estimation by Analogy relies on historical information and past experiences, leading to more accurate predictions. Here we compare the current tasks with the issues that teams have already faced the challenges in the past. As a result, the reliability and accuracy are increased in Estimation by Analogy.
2. Time-Saving in Project Planning: The utilization of analogies saves valuable time during the project planning phase. Instead of creating estimates from scratch, project teams can use the existing information about previous efforts and outcomes. This efficient approach reduces the time required for estimation and makes the team ready for the critical aspects of project planning and execution.
3. Enhances Team Coordination: The process of comparing current tasks with historical data fosters a common understanding among team members. This shared knowledge helps align team members on expectations and potential challenges. As a result, Estimation by Analogy contributes to improved team coordination and collaboration, reducing the likelihood of conflicts and misunderstandings.

Disadvantages of Analogy Estimation

1. Bias in the Estimation Process: Analogous Estimation is tolerant to bias as it heavily relies on historical data and past experiences. If previous efforts were inaccurately estimated or if there were unforeseen challenges, the estimation process may inherit those biases. This could lead to an overemphasis on historical factors, resulting in biased project effort calculations.
2. Limited Applicability in Unique Projects: Analogous Estimation may be less applicable in projects with unique or uncommon requirements. In cases where the project involves tasks that significantly differ from previous projects, historical data may not accurately reflect the efforts required.
3. Potential Ignorance of Subject Expertise: In certain situations, team pressure or political considerations may override project-specific calculations or insights from subject matter experts. The dependence on historical data may lead to overlooking the expertise of individuals who possess valuable insights into the unique aspects of the project. This can fail to account for critical project efforts.

What is Estimation by Relative Sizing?

Estimation by Relative Sizing considers the complexity of other tasks is considered while estimating the project. It involves a comparison of the parameters from the current tasks with similar types of tasks to identify and calculate the project efforts. This estimation method does not make it compulsory to find the exact numerical estimate. It estimates the project efforts just by comparing them with tasks of similar categories.

1. Estimation by relative sizing includes the comparison of ongoing activities to similar types of activities using the user scenarios and Story Points. It means that the complexity of the user story is compared with the user story of other tasks.
2. The user story with the highest complexity is assigned a higher number of story points. Thus, we can compare the project tasks in terms of story points.

Advantages of Relative-size Estimation

1. Easy Adaptability: The historical data is not always available or accessible. But the comparison of tasks with similar activities is easy. We do not need to recalibrate the estimation metrics to adapt to the requirements. Thus, the Estimation by Relative Sizing is easy to use.
2. Enhanced Customer Satisfaction: The stakeholders or customers become more satisfied by getting comparisons between similar tasks to estimate the project resources. Thus, it is easy to convince them of parameters such as project deadlines or delivery.
3. IT Reduces Bias: The project experts do not need to rely only on the first piece of information to make a decision. Also, absolute values do not influence the teams easily. This reduces the bias in the project estimation and increases the accuracy.

Disadvantages of Relative-size Estimation

1. Unnecessary Conflicts due to Relative Sizing: The understanding of like or similar tasks may vary for each team member. This leads to conflicts in terms of effort identification. Also, the complexity may increase due to different subjective understandings.
2. Dependency on Skilled Team: The scale for Relative Sizing differs from project to project. Due to this, Relative Sizing is not very relevant if the team is not skilled enough. The unskilled team members face difficulty in accurate planning which causes the project estimate to become inaccurate.
3. Less Precise for Smaller Projects: It is easy to compare the ongoing tasks with the projects on a large scale. However, if the project has small tasks, the relative sizing becomes inaccurate even if they are well-defined. This makes Estimation by relative sizing less precise for the smaller project.

Conclusion: Estimation by Analogy and Relative Sizing

In conclusion, estimating a Project is all about knowing the resources and crucial efforts done to complete the tasks. Project Estimation is an important part of Project Management that helps us to find the cost, time, and effort per unit task. The techniques of Estimation by Analogy and Relative Sizing help the project managers easily find out when the projects will be delivered and with how many resources. Now, you are clear with the Project Estimation Techniques. You can easily implement these to make your project successful.

FAQs: Estimation by Analogy and Relative Sizing

1. Can Relative Sizing and Analogous Estimation be applied in Non-Agile Projects?

The Project Estimation techniques apply to any type of project management approach whether it is an Agile or Non-Agile Process. They just focus on finding out the cost and resources required for the project.

2. What is Parametric Estimation in Project Management?

Parametric Estimation uses the parameters and values to estimate the project. Here, the statistical parameters such as cost per unit of work and quality of the unit of work are considered for project estimation.

3. What are the scales available for the relative sizing?

The various scales available for Relative Sizing Estimation are Story Points in which numerical points are assigned to the task’s complexity. Also, the Fibonacci Sequence, or a power of two sequences is used in this process. Apart from this, T-shirt Sizes are used to qualitatively assign complexity to user stories.

4. How to Overcome Bias in Analogous Estimation?

The Analogous Estimation makes the estimation biased toward specific factors. However, we can easily reduce the bias by taking inputs from different team members and stakeholders. We can also survey within the organization to make project estimation more precise.