Agile Sizing and Estimation

Agile Sizing and Estimation are important planning tools in the agile project management process and are crucial elements covered in the PMI Agile Certified Practitioner (PMI-ACP) exam. These tools aid in the effective sizing and estimating of user stories or features, thereby enhancing the predictability and control of agile projects.

What is Agile Sizing and Estimation?

Agile Sizing and Estimation refer to the process of determining the ‘size’ or effort required for a task, item, or user story in an agile project. It involves employing various techniques for sizing and estimating tasks, taking into consideration factors such as complexity, effort required, and the amount of work involved. This will later be translated into a timeframe using team’s velocity.

Techniques in Agile Sizing and Estimation

Several agile sizing and estimation techniques can be applied depending on your specific project needs:

1. T-Shirt Sizes

In this method, work items are categorized into ‘sizes’ ranging from XS, S, M, L, XL, XXL, similar to t-shirt sizes. This is a relative estimating technique, where each size represents an increment of effort. Usually, one size is twice as large as the previous one, and half the size of the next.

2. The Bucket System

This method utilizes buckets (representating size categories). You place work items into these buckets based on their relative sizes. Buckets often follow a sequence like 0, 1, 2, 3, 5, 8, and 13, similar to the Fibonacci sequence. This method is useful for large backlogs.

3. Fibonacci Sequence

The Fibonacci Sequence is a series of numbers where the next number is found by adding up the two numbers before it. In agile estimation, the Fibonacci sequence (0, 1, 2, 3, 5, 8, 13, 21, and so on) is typically used to relate the complexity of delivering a story.

4. Planning Poker

Planning Poker is a fun, team based estimating technique. Each team member is given a deck of cards with numbers following the Fibonacci sequence. For each user story, after a brief discussion, every team member selects a card representing their estimate of the effort required to complete the story. If there are wide variances, further discussion ensues until the team agrees on an estimate. This method engages everyone and tends to lead to more accurate estimates.

When to Use Agile Sizing and Estimation Techniques

Agile Sizing and Estimation techniques are used during sprint planning, which occurs at the start of a new sprint. The team discusses the product backlog items, sizes and estimates using one of the mentioned techniques, and prioritizes work for the next sprint based on the estimates, capacity of the team and priority of items.

Key Benefits of Agile Sizing and Estimation

• Improves Accuracy: Agile Sizing and Estimation techniques, when applied correctly, improve the accuracy of project timelines and budgets.
• Enhances Transparency: Regular sizing and estimation meetings ensure that all team members understand the effort and complexity involved in each task or user story, thus enhancing team’s transparency.
• Optimizes Prioritization: Proper sizing and estimation of tasks helps in better prioritization and ensures that the most important tasks are tackled first.
• Promotes Team Accountability: When the entire team collaboratively participates in the estimation process, it fosters a sense of collective ownership and accountability.

Agile Sizing and Estimation techniques are skills every agile practitioner aspiring for the PMI Agile Certified Practitioner (PMI-ACP) certification must intensively learn and practice. Mastering these techniques will not only help you pass the certification exam but will also go a long way in successfully managing agile projects and making you a competent and agile-ready project manager.

Practice Test

True/False: Agile sizing and estimation forms an essential part of Agile project planning.

• True
• False

Answer: True

Explanation: Agile sizing and estimation practices help in determining the amount of work that can be taken up in a Sprint and help with release planning.

Which type of estimation is used in Agile methodologies?

• A. Long-term estimation
• B. Minute level estimation
• C. Relative estimation
• D. Absolute estimation

Answer: C. Relative estimation

Explanation: In Agile methodologies, relative estimation is used which involves comparing the size of one piece of work (story) to another.

Multiple Select: What are some methods used in Agile for sizing and estimation?

• A. Story points
• B. Planning poker
• C. T-shirt sizes
• D. Fixed Value

Answer: A, B, and C

Explanation: Story points, planning poker, and T-shirt sizes are popular techniques used in Agile for project sizing and estimation.

True/False: In Agile, estimation accuracy improves as project progresses.

• True
• False

Answer: True

Explanation: In Agile, as the team delivers increments of work, they gather feedback and learn which improves the accuracy of their future estimations.

Single select: What does a Story point in Agile represent?

• A. A defined unit of time
• B. The complexity of the story
• C. The number of team members
• D. The priority of the story

Answer: B. The complexity of the story

Explanation: A story point represents the amount of work, complexity and unknown factors about a task/story.

True/False: Agile teams estimate work to commit to exact timelines.

• True
• False

Answer: False

Explanation: Agile teams estimate to understand the size of work, not to commit to exact delivery dates since Agile is more about flexibility and adaptability.

Single select: What is the primary purpose of Agile estimation?

• A. Making project budget
• B. Determining exact delivery dates
• C. Prioritizing stories
• D. Choosing which tasks to complete first

Answer: C. Prioritizing stories

Explanation: Agile estimation primarily helps in deciding the order in which stories should be implemented based on complexity and effort required.

True/False: Only project leaders can provide estimates in Agile.

• True
• False

Answer: False

Explanation: In Agile, all team members, including developers and testers, are involved in sizing and estimation process.

Single select: Which technique involves the entire team in Agile estimation?

• A. Planning poker
• B. Expert estimation
• C. Algorithmic estimation
• D. Top-down estimation

Answer: A. Planning Poker

Explanation: In planning poker, all team members make an estimate and then discuss the difference in views to reach consensus.

True/False: In Agile, estimation is a one-time activity performed at the beginning of the project.

• True
• False

Answer: False

Explanation: In Agile, estimation is a continuous activity as stories are broken down, understood better or new stories are added during the project lifecycle.

Multiple Select: Which parameters influence story point estimation in Agile?

• A. Complexity
• B. Effort
• C. Risk or uncertainty
• D. All of the above

Answer: D. All of the above

Explanation: Story point estimation in Agile takes into account the amount of work, complexity and uncertainties involved in a story.

Single select: In Agile, team velocity is calculated by?

• A. The amount of time taken to complete a story point
• B. The number of story points that a team can complete in one iteration
• C. The total number of story points completed in a project
• D. The average number of story points completed by all the teams in the organization

Answer: B. The number of story points that a team can complete in one iteration

Explanation: Team velocity is a measure of the amount of work a Team can handle during a single Sprint/iteration and helps in future sprint planning.

True/False: In Agile, smaller stories are more accurately estimated.

• True
• False

Answer: True

Explanation: As stories are broken down into smaller, more manageable pieces, the team can understand and estimate them better.

Single select: What factor does not impact the estimation of story points in Agile?

• A. Size of the story
• B. Complexity of the story
• C. Priority of the story
• D. Risk associated with the story

Answer: C. Priority of the story

Explanation: Priority of the story is typically used for backlog organization, not for story point estimation which focuses on size, complexity and risk.

True/False: All user stories within a project should have the same story point value.

• True
• False

Answer: False

Explanation: Not all user stories will have the same complexity or require the same amount of work. Story points allow for differentiation between stories based on these factors.

Interview Questions

What is Agile Estimation and Sizing?

Agile Estimation and Sizing is a technique used in Agile project management to estimate the size, effort, and duration of a project or task. It uses different techniques like Relative Sizing, Story Points, Planning Poker, T-Shirt Sizing, and Ideal Time.

What is the purpose of Agile Estimation and Sizing?

The purpose of Agile Estimation and Sizing is to create a rough estimation of the total effort that will be required to complete a project or specific tasks. It provides the project team with a better understanding of the workload, which allows more accurate scheduling and resource allocation.

What is Planning Poker in Agile Estimation and Sizing?

Planning Poker is an estimation technique in Agile that utilizes consensus-based estimating. Team members make estimates by playing numbered cards face-down on the table, instead of speaking them aloud, until everyone has placed a card. The cards are then revealed, and the results are used to create an estimate.

What are Story Points in Agile Estimation and Sizing?

Story Points are a unit of measure used in Agile project management and development for expressing an estimate of the overall effort required to fully implement a backlog item or any other piece of work.

What is the Ideal Time in Agile Estimation and Sizing?

Ideal time is a form of measurement used in agile where teams calculate how much time a task would take to complete if there were no interruptions. It helps Agile teams to break down the project into manageable tasks.

How is velocity used in Agile Estimation and Sizing?

Velocity in Agile is a metric that predicts how much work an Agile team can successfully complete within a two-week sprint, based on past performance. It is used in Agile Estimation and Sizing to forecast future sprints.

What are Agile Sizing and Estimation Techniques?

Several techniques can be used for Agile Sizing and Estimation, these include Relative Sizing, Story Points, Planning Poker, T-Shirt Sizing, Ideal Time, and Velocity. These techniques allow the team to estimate the size and effort of the project or tasks more accurately.

Why does Agile prefer relative units over absolute units for Estimation and Sizing?

Agile prefers relative units over absolute units because they are more efficient and accurate at reflecting complexity, uncertainty, and risk. It allows the team to compare the size of features or stories to each other, which is faster and more intuitive.

In the context of Agile Sizing and Estimation, what is meant by ‘burn-down chart’?

A burn-down chart in Agile is a visual representation of work left to do versus time. The outstanding work (or backlog) is typically on the vertical axis, with time along the horizontal. This effectively shows the total effort remaining and how quickly the team is accomplishing work.

What is T-shirt Sizing in Agile Estimation?

T-Shirt Sizing in Agile Estimation refers to the practice of estimating the relative sizes of tasks or stories by allocating them T-shirt sizes like XS, S, M, L, XL. These sizes represent a range of sizes, and their associated effort, complexity and uncertainty.

How does the use of Fibonacci sequence help in Agile Estimation and Sizing?

The use of the Fibonacci sequence in Agile Estimation and Sizing helps to reflect the inherent uncertainty in estimating larger items. A Fibonacci sequence forces the choice of a larger number when there is uncertainty, which helps teams considering the risks and efforts more cautiously in the case of larger tasks.

Why is it important to include the whole team in the Agile Estimation and Sizing process?

Including the whole team in the Agile Estimation and Sizing process is important because it helps to provide different perspectives and absorb the collective wisdom. This can help to produce more accurate and realistic estimations.

How is ‘effort’ different from ‘duration’ in Agile Estimation and Sizing?

In Agile Estimation and Sizing, ‘Effort’ refers to the total amount of time that would be spent on a task if a person was working on it uninterruptedly. ‘Duration’, on the other hand, is the total time from start to finish of a task, including any interruptions or delays.

What are the benefits of Agile Estimation and Sizing?

The benefits of Agile Estimation and Sizing include better prediction of project timelines and resources needed, improved understanding of the size and complexity of the work, aid in prioritizing tasks, enhancement of team collaboration and learning, and increased stakeholder satisfaction by setting realistic expectations.

Describe how the cone of uncertainty is applied in Agile Estimation and Sizing?

The cone of uncertainty is a model used in Agile Estimation and Sizing that describes the uncertainty and risk that exist when estimating the effort, time, or cost of work. As the project progresses, the cone narrows and estimates become more accurate. It underscores the idea that early estimates are subject to large degrees of uncertainty, which decreases as the work progresses and more information becomes available.