Blog

Reach Us

Evidence-based Estimation

27 Oct 2014

Evidence-based Estimation

An analogy I can think of is… I want my dart to hit the dart board, and not necessarily the bull’s eye…. as it calls for a lot of details which apparently is missing during estimation. However, if my dart doesn’t hit anywhere on the dart board… it’s almost like shooting in the dark; a very disappointing estimation scenario.

A vast chunk of new teams struggle in arriving at a correct project estimate; with most them failing due to a huge variation (with estimated Vs actual)! Very few succeed in this journey by coming closer to the actual in the initial cycles itself.

Project managers in traditional development focus on detailed scope, so that the cost, estimate, and time are accurate and frozen before kick starting a project. How far this is successful and precise is debatable! In agile projects, during release planning the development team arrives at a high-level estimate for each story in the product backlog normally in story point which aids in finer estimation during sprint planning. This helps the team to get started, rather than wait for all the project details to get finalized.

Story point is an arbitrary measurement of a feature’s size relative to other features and not the time needed to complete a feature. For example, by looking at the picture of the whales you cannot determine the exact age or weight of each whale but can compare the size of each with respect to each other. This is a very handy approach as detailed information to estimate the effort may not be available so early. Story points are used to calculate how many user stories a team can complete in a sprint which is termed velocity.

The story point size assumptions are interpreted using an estimation scale, the most common ones include numeric sizing (1 through 10), t-shirt sizes (XS, S, M, L, XL, XXL, XXXL), Fibonacci sequence (1, 2, 3, 5, 8, 13, 21, 34, etc.), etc.

A team to get started with story point estimating must be clear, synchronous, and agree upon the below aspects (I call it the ‘Five subtle rules’ as they are hidden and work at the back of our mind.).

Common reference – Each team member estimating should have a same reference. For example, the size L to measure a story point size should be the same criterion for everyone in the team. Any conflict with respect to the reference index results in huge variation and wrong estimation. Agreeing upon a common reference is very critical.

Collective wisdom – Estimation is a team activity and hence all should participate in this. Having one person do this will be a huge risk as the margin of error will be high! However, a collective decision helps in arriving at a common estimate which in all probability will be accurate.
In addition, during relative estimation the team should also take into account the effort, complexity, and uncertainty for every story before arriving at a number.

Effort – How much effort a story would take to complete, relative to the reference story.

Complexity – How complex is the story with respect to the reference story.

Uncertainty – How much risk/unknowns a story holds relative to the reference story

Even with this common agreement, it may still take a few iterations for the team before arriving at a common estimation value. With estimation being definitely hard, how do we get the best estimates of story size?

Why not take a closer look at “Evidence-based estimation”, learn from experience, become proficient with every calibration, and adopt during the initial project estimation phase to understand its true benefits!

Here is the approach a team should take to proceed with “Evidence-based Estimation”:

Let’s consider a scrum team of 7 members commence a 2-week sprint of 10 working days. With 6 hours as the effort per day, the capacity would approximately be 7 * 10 * 6 = 420 hours.

  • During the 1st sprint planning meeting, the team begins story estimation from scratch with no story points assigned to stories in the product backlog.
  • A story is picked from the product backlog followed by task and time breakdown for each. This step continues till the estimated capacity adds to about 400 hours/5 stories (considering the average team capacity is 420 hours).
  • Through the sprint, the team works towards completing all the planned stories.
  • Just before the retrospective meeting, the team assembles to story point the completed stories (definitely now with some experience/evidence).
  • Among the 5 stories, the team picks the one with medium effort, complexity, and uncertainty and assigns a story point (keeping the 5 subtle rules in mind). For example, when we take an estimation scale of 1, 2, 3, 5, 8, 13; this story is assigned a story point of 3 and it becomes the common reference story. A closer look at this exercise clearly indicates that the story point number is emerging out of working experience/evidence and not by mere guess work!
  • The team continues story point estimation for all the stories in Sprint 1 (per Step 5) and assigns a value lower, higher, or the same when compared to the reference story point.
  • As the team proceeds from one story to another, the comparative reference points become varied apart from being evident which helps them with better estimation. At this point if the team feels a need to refine the previous estimates, they can. The idea is to get better estimates with experience that are realistic.

The teams may decide to use this estimation during the initial few sprints till they are confident of the process. With experience, the team becomes an expert and are equipped at deriving an almost accurate story point during the release planning (rather than after the completion of a sprint), thereby aiding in better agility and transparency.

Retrospectives

24 Mar 2014 - 1

The Power of Anonymous Retrospectives

The Scrum values – Openness, Commitment, Focus, Respect and Courage are the foundation for the behavior and practices in Scrum. It’s difficult for organizations to adhere to these values from the onset of their Agile journey. Agility is about behavior and cultural changes and the values listed can’t be demanded, they have to be earned by creating transparency and is a journey that never ends.

While coaching Agile teams over the years, I have learned that no matter how open and transparent the organization is, there will be some individuals that won’t openly speak up. They are mostly introverts and have a phobia of public speaking. They will limit their interaction to a bare minimum. In some organizations engineers carry the management fear. They feel like they are being observed and anything and everything they say will reflect in their yearly performance appraisal and they clamp up. In either of these situations or situations similar to these, the Anonymous Retrospective helps get the real pulse on the floor. It helps all the participants open up and talk about what they really feel deep within about the organization, the culture, the people, the leadership, the technology, the motivation factor, etc.

So what is Anonymous Retrospective? As the name suggests, all data collected is completely anonymous. The first rule of the Anonymous Retrospective is the data collected has to be truly anonymous and there should be no attempt to tie the same to any individual – either through the language used to describe it or with an handwriting match. What I normally do is I put an empty container in the middle of the room and  give each participant a bunch of Post-its. I ask them to jot down their thoughts on what is working well and the areas that need improvement. I emphasize to the participants that this is a Anonymous Retrospective and encourage them to share their thoughts without having an iota of worry. I then ask them to fold the post-its and put it in the empty container. I normally time box this to around 25 to 30 minutes.

Once everyone is done, I get the container with the post-its and give it a good mix. Then I appoint someone neutral to take notes on their laptop and help me with basic categorization. I pick each note and try to read it as verbatim as possible, except for certain cases where there are personal attacks. I read them one at a time in front of the entire room, the person taking the notes captures it, and then I tear the post-it in front of all the participants and put it in the trash can to maintain confidentiality. This is what I mean by “Anonymous”.

Anonymous Retrospective will generate plenty of data which has to be validated for its accuracy. Once all the data points are collected, work with the participants in the room to finalize the categorize the data, and generate information by connecting data in each category together.  Following this put an action plan together to address each category. Most likely you will need multiple sessions to do this… but remember you now have some solid facts with which you can incrementally introduce improvements. This is what the power of Anonymous Retrospective is!

I am happy to hear your thoughts.

Tesco certificate

27 Dec 2012

Tesco’s Success Story with Agile Adoption

 

 

Over the past 2 years I have been helping Tesco’s Dotcom International Grocery Home Shopping (IGHS) group in the capacity of Agile Coach to build their eCommerce Platform. Tesco Dotcom’s challenge was to take the world’s largest grocery website international to multiple countries outside UK as quickly as possible and be the market leader. 

As the saying goes, “The proof is in the Pudding” …. By using Agile as a Software Development Methodology  with a  combination of Scrum, XP, Kanban and lean principles of choice, Tesco was able to launch their Dotcom operation to new countries regularly and is currently live in 5 countries within the span of just over 2.5 years. This group with several Agile teams distributed across 2 geographies was able to bag 4 major awards within the organization, including the “Tesco – IT project Cup” of the year.

It is my privilege and honor to be part of a journey with this passionate team that was constantly hungry to take the Agile adoption from one level to another tirelessly through continuous Inspection and Adaption and both the passion & Hunger continues….

Scrum team organization - Feature teams

29 Jul 2009 - 3

Scrum team organization – Feature teams or Component teams – Part 2

Component Teams (CT) are specialized teams organized around the architecture of the product under development. Examples of such teams are UI / User experience teams, Database design and modeling teams, team of Architects, Security team, etc.

A typical component based scrum team is more or less similar to a feature team i.e. each CT will have 3 to 4 developers, 2 to 3 testers, a Product Owner & Scrum Master with Documentation and Architect representation as needed.

The top node of the diagram “Theme/Epic”depicts customers value add features (Features that customer value). Think of this as some high level requirement that marketing will use in their presentation to advertise a product. This value add feature might not be small enough to finish in one sprint and gets decomposed in to multiple smaller features i.e. Feature 1, Feature 2, Feature 3, and Feature 4. What this essentially means is, once Feature 1 through 4 are done in its entierty, the top level Theme/Epic is “Done”.

The stories for component based teams are fed by these decomposed features Feature 1, Feature 2, Feature 3, and Feature 4. As the diagram shows, Feature 1 is dependent on Component Teams C1, C2 and C3. Similarly, Feature 2 is dependent on component team C1 and C2, Feature 2 is dependendent on CT C1 and C3 and so on. Component teams in general provide functionality and serve multiple Features. Component teams generally don’t generate products that get shipped to the customer. But they develop functionality that is consumed by feature teams and indirectly helps add value to the features being delivered to customers.

If organizations are structured in a way that specialized teams are spread globally then forming component based teams might make sense. Component based teams are great to keep site affinity, work across different timezones and also to keeping team culture intact. But it also comes at an expense of management overhead.

Few challenges with component teams based on my experience

  1. There is overhead of integrating component team’s delivery with the top level features. In the example above, when C1, C2 and C3 finishes the deliveries for Feature 1 they have to be integrated together in Feature 1.
  2. To ensure all scrums are aligned well to deliver end-to-end customer functionality, it will take lot of upfront planning as well as tracking during the entire sprint.
  3. In my experience, with component based teams it’s very difficult to deliver thin slice of end-to-end functionality at end of each iteration because feature team needs time to harden (stabilize code base + write integration tests) their code with component team code delivery.
  4. Since component team serves multiple features teams, negotiation needs to happen between Feature Team and Component teams to avoid starvation. For Ex. In the diagram above Component Team C1 gets requirements from Feature 1, Feature 2, and Feature 3. In the upcoming iteration let’s say C1 can only serve Feature 1. In this case Feature 2 and Feature 3 teams will have to wait until next iteration before their needed functionality is delivered and will be starved.

Thus, for component teams to succeed open communication channel should be established throughout the organization.

Please share your experiences.