Effective Time Estimation in Software Testing

In the realm of software development, the role of a software tester is both critical and challenging, particularly when it comes to estimating the time required for testing.

This guide aims to equip us with a deep understanding of various time estimation techniques and best practices, helping us to navigate through this crucial phase effectively.

The Significance of Precise Time Estimation

Accurate time estimation is a cornerstone in software testing. It not only ensures that the software quality is upheld but also plays a vital role in aligning product delivery with projected timelines. A well-estimated testing schedule can greatly impact the overall success and market readiness of a product.

Let’s discuss the approaches on how to estimate your testing activities.

The Work Breakdown Structure Approach

One effective way to estimate testing time is by using the Work Breakdown Structure (WBS) approach.

This method involves dissecting the testing process into smaller, more manageable segments. By doing so, you can allocate time and resources more effectively, anticipate dependencies between tasks, and enhance overall project transparency and collaboration.

Here’s a step-by-step guide on how to create a WBS, specifically tailored for a software testing project:

1.) Start by clearly defining the main goal or objective of your software testing project. This could be something like “Test the X software for release”.

2.) Break down the project objective into major deliverables or key components. These could include:

• Test Planning
• Test Case Design
• Test Execution
• Defect Reporting
• Test Closure

3.) For each major deliverable, break it down into smaller, more specific tasks. For example:

Test Planning:

• Identify testing scope
• Define test objectives
• Resource allocation

Test Case Design:

• Create test cases for functional testing
• Develop test cases for performance testing

And so on for each major deliverable.

4.) Assign a unique identifier to each element in the WBS. This helps in tracking and managing the work.

For example, 1.0 for Test Planning, 1.1 for Identify testing scope, etc.

5.) Decide the order in which the tasks should be executed. Some tasks may need to be completed before others can begin.

6.) For each task, estimate the resources (like manpower, tools, etc.) and the time required to complete it. This helps in planning and scheduling the project.

7.) Use a diagram or chart to visually represent the WBS. This could be a tree structure showing the hierarchical relationship between the project objectives, deliverables, and tasks.

8.) Review the WBS with your team and stakeholders to ensure that nothing is overlooked and that it aligns with the project objectives. Make necessary refinements.

The WBS should be a living document that can be updated and refined as the project progresses and more information becomes available.

The Three-Point Estimation Technique

The Three-Point Estimation technique considers three potential scenarios:

• the best case (optimistic estimate),
• the most likely case (realistic estimate),
• the worst case (pessimistic estimate).

By computing a weighted average of these scenarios, you can attain a balanced and realistic time estimate, minimizing the risk of underestimation.

User-centric Estimation

This is a powerful methodology for estimating the time needed for software testing, as it focuses on how the software will be used in real-world scenarios. It involves examining various user scenarios and their complexity, thereby ensuring that the software is tested thoroughly from a user-centric perspective.

This approach provides a structured and comprehensive way to understand and measure the testing effort required. Here’s a detailed explanation of how it aids in time estimation:

1. Each use case represents a functional scenario in which a user interacts with the software. Identify these cases to provide a clear outline of what needs to be tested.
2. Use cases vary in complexity. By analyzing each use case, you can determine the effort required to test it. Complex use cases involving multiple system interactions or user steps will generally require more testing time.
3. Also, this methodology ensures that all functional aspects of the software are covered. By estimating the time for each use case, you can ensure comprehensive coverage, leading to more accurate overall time estimates for the project.
4. Create specific scenarios for each use case, which can be time-estimated individually. This granular approach to planning allows for more precise time estimates.
5. Some use cases may have higher risks associated with them (like those involving critical business functions). Identify these to allocate additional time for thorough testing.
6. Understanding the dependencies between use cases helps in planning sequential or parallel testing activities, influencing the time estimation.

Imagine a software application for online banking. Some of its use cases might include:

• Use Case 1. User logs into their account.
• Use Case 2. User transfers money to another account.
• Use Case 3. User views their transaction history.

For time estimation:

• Use Case 1. Might be straightforward, requiring less time to test basic login functionality.
• Use Case 2. Involves multiple steps (entering account details, verification, transaction processing), and thus, requires more time for testing, including edge cases like incorrect account details or network failures.
• Use Case 3. Involves retrieving and displaying data, requiring tests for accuracy and performance. This might require moderate time depending on the data complexity.

By estimating the time needed for each of these use cases based on their complexity and the number of scenarios within each, you can provide a comprehensive time estimate for the entire project. For instance, Use Case 1 might take 5 hours, Use Case 2 could take 15 hours due to its complexity, and Use Case 3 might require 10 hours. Thus, the total estimated testing time for these core functionalities would be 30 hours.

The Ad-Hoc Estimation Method

In situations where a rapid and less formal estimation is required, the Ad-Hoc method can be particularly useful. This approach draws upon the collective experience and judgment of the testing team, making it an effective strategy, especially when the team has prior experience with similar types of projects.

Here’s a guide on how to conduct ad-hoc estimation:

1. Bring together the team members who will be involved in the testing process.
2. Give an overview of the project, including its objectives, key features, and any known challenges. This helps the team to understand what they will be estimating.
3. Encourage team members to draw upon their past experiences with similar projects. This could involve recalling how long it took to test similar features or deal with comparable challenges in the past.
4. Conduct an open brainstorming session where team members discuss the various aspects of the project and share their thoughts on potential complexities and time requirements.
5. Ask each team member to provide their own estimate for the project or for specific components of the project.
6. If there are significant differences in the estimates provided by team members, discuss these variances. Understand the reasoning behind different estimates and use this discussion to refine the overall estimation.
7. Based on the discussion, try to reach a consensus or an average of the estimates provided. The goal is to come up with a realistic timeframe that reflects the collective experience and insight of the team.
8. Take into account any external factors that might influence the testing time, such as resource availability, tooling, external dependencies, and potential risks.
9. Even though this is an informal approach, it’s important to document the final estimation along with the rationale behind it. This helps in future reference and in improving the estimation process.

As the project progresses, be prepared to review and adjust your estimates.

The Wideband Delphi Method

The Wideband Delphi method is a consensus-driven approach that involves experts. Through a series of iterative discussions and reviews, this method allows the team to converge on a common estimation, ensuring a comprehensive and well-rounded perspective. In order to employ this method, please follow the instruction:

1. Select a group of experts, typically consisting of project members with diverse knowledge and experience relevant to the project.
2. The process begins with a meeting where the project’s scope and objectives are outlined.
3. Each expert independently writes down their estimate, such as the time required to complete a task.
4. The initial estimates are then shared anonymously with the group.
5. The group discusses the estimates, focusing on why certain estimates differ significantly from others.
6. After the discussion, experts independently revise their estimates. This process of estimation, presentation, and discussion is repeated in several rounds.
7. Through these iterative rounds, the group’s estimates usually converge towards a consensus.
8. Once a consensus is reached, the final estimate is documented and used for project planning.

Proportion Allocation Method

This technique involves assigning a percentage of effort to each stage of the testing cycle. By doing so, you can effectively prioritize tasks and allocate resources, ensuring that effort is focused on the most critical areas of the testing process.

To use this method,

1. Break down the project into its main phases or components. For example, planning, test case design, test execution, defect reporting, and test closure.
2. Assess the importance and complexity of each phase.
3. Allocate a percentage of the total project effort or resources to each phase, based on the evaluation done in the previous step. These percentages reflect the relative amount of work or resources each phase is expected to require.
4. Multiply the total estimated effort or resources for the project by the percentage allocated to each phase. This gives you an estimate of the effort or resources required for each component.

Consider a software testing project with an estimated total effort of 100 person-days. If test planning is estimated to take 10% of the effort, test case design 20%, test execution 50%, defect reporting 10%, and test closure 10%, then the effort distribution would be:

• Test Planning = 10 person-days (10% of 100)
• Test Case Design = 20 person-days (20% of 100)
• Test Execution = 50 person-days (50% of 100)
• Defect Reporting = 10 person-days (10% of 100)
• Test Closure = 10 person-days (10% of 100)

This example illustrates how the Proportional allocation method provides a straightforward way to distribute effort across various stages of a project.

Poker Planning and T-Shirt Sizing

In Agile environments, innovative techniques like Poker Planning and T-Shirt Sizing are employed. These collaborative methods encourage team discussions to reach a consensus on the complexity and size of tasks, focusing on relative effort rather than precise time metrics.

Recommendations

1. Organize meetings and discussions with stakeholders to gain a deep understanding of the project requirements. Use these insights to inform your estimation process.
2. Break down the overall testing process into smaller, manageable tasks.
3. Review past projects with similar scopes or requirements. Analyze the data to understand how much time was spent on similar tasks and use this information to inform your current estimates.
4. Engage team members who have relevant experience or expertise in similar projects.
5. At the start of the project, conduct a risk assessment to identify potential challenges that could impact the timeline. Factor these risks into your time estimates to ensure they are realistic.
6. Ensure that you include time for setting up and maintaining the necessary test environments and tools in your estimation. This often-overlooked aspect can significantly impact the overall timeline.
7. Establish a routine for revisiting your time estimates. As the project progresses and more information becomes available, adjust your estimates accordingly to reflect the current understanding of the project’s scope and requirements.

Mastering the art of time estimation in software testing is pivotal for the success of software projects. By employing these techniques and adhering to established best practices, you can significantly enhance the precision of your time estimates. This not only ensures the maintenance of software quality and adherence to delivery schedules but also reinforces the vital role of the testing phase in the software development lifecycle.

💖 Do not forget to follow us on Linkedin and Facebook to learn more about software testing and tech news.

💎 Try TestCaseLab for free with a 30-day trial subscription here!

Please share this article with those who may benefit from it.

Thank you!