Behavior driven development: How does it work?

I’ve used Behavior Driven Development (BDD) in many software projects over the years. It’s a collaborative approach that aligns developers, testers, and business stakeholders to build software that solves user problems. You’ll learn what BDD is and why it’s so effective.

Understanding Behavior Driven Development (BDD)

Behavior Driven Development (BDD) has transformed software development. It is a methodology for describing system behavior in terms of users. BDD evolved from Test Driven Development (TDD) in 2006 when Dan North and Chris Matts identified the limitations of TDD and created a new methodology called BDD.

BDD is different from TDD because it:

• Focuses on behavior, not the technical implementation
• Utilizes natural language specifications
• Requires collaboration between developers, testers, and business stakeholders
• Focuses on user stories and scenarios

The purpose of BDD in software development is to:

1. Improve communication between technical and non-technical team members.
2. Ensure the software meets the business requirements.
3. Produce living documentation so the project continues long-term.
4. Minimize miscommunications and rework.

BDD promotes collaboration and a shared understanding. It eliminates the gap between business needs and a technical implementation. As a result, the project will have a more efficient development cycle, and you’ll provide a higher quality software product.

The BDD Process and Workflow

The BDD process itself is divided into three primary stages:

1. Discovery: Team members collaboratively discuss and define the desired behavior of the system.
2. Formulation: Behaviors are documented in a specific format using Gherkin.
3. Automation: Behaviors are automated as executable specifications.

Interestingly, the Discovery stage represents 80% of the total effort to implement BDD. Automation makes up just 20% of the total BDD implementation effort.

You need at least three specific roles to successfully implement BDD:

Gherkin is a key concept in BDD. It’s a structured language that describes software behavior. Here’s a simple example of a Gherkin scenario:

Given [a certain initial context]
When [something happens]
Then [the expected result]

Scenarios and acceptance criteria are the foundation of BDD. They are specific, executable descriptions of how the software should behave. The development team uses these specifications to build functionality and automated tests.

BDD Frameworks and Tools

The most popular BDD frameworks are Cucumber, SpecFlow, and JBehave, each of which has its own set of capabilities to aid in the BDD process.

Cucumber is the most widely used BDD framework, and for good reason. It supports multiple programming languages and integrates with various development environments. You can use Cucumber for natural language parsing, test execution, and reporting.

The best BDD software tool for you depends on:

• The programming language your team is most comfortable with
• How the tool integrates with current software applications
• Reporting and documentation requirements
• The learning curve and available documentation for the tool

Selecting the right BDD software tool is a critical decision, as it will play a significant role in the success of your project. Therefore, consider your team’s needs and capabilities carefully when making this decision.

Implementing Behavior Driven Development

Implementing BDD with a development team requires strategy and careful execution. Begin by teaching team members about BDD principles and how to apply them. Then gradually introduce BDD in smaller features or projects.

The key principles of writing good behavior specifications are:

1. Using simple, easy-to-understand language
2. Ensuring the behavior adds business value
3. Not including technical details in the scenario descriptions
4. Making behaviors as independent and atomic as possible

Common mistakes made when implementing BDD include:

• Writing overly complex behaviors
• Limited stakeholder involvement
• Inconsistency in how BDD is applied
• Failing to maintain behaviors as the requirements change

BDD also pairs well with Agile, as it provides a clear, executable behavior for each iteration. You can also scale BDD for larger projects by:

1. Defining a consistent BDD process across the teams
2. Building a strong automation testing strategy
3. Leveraging BDD management tools to keep everything organized
4. Revisiting and iterating on BDD as needed
   
   

Benefits and Challenges of BDD

BDD has several benefits when developing software:

1. Better communication between technical and non-technical team members
2. Clearer idea of project requirements
3. Fewer defects and less rework
4. Living documentation that grows with the project

Teams that use BDD see a 25% reduction in communication issues between team members, allowing them to complete development cycles more efficiently and deliver higher quality software products.

Improved software quality is a result of:

• Early defect detection
• Clear acceptance criteria
• Continual validation of system behavior

The main challenges of implementing BDD include the initial learning curve, team member resistance, the time investment to write and maintain scenarios, and ensuring everyone follows BDD consistently.

You can help mitigate team member resistance to BDD by:

1. Clearly communicating the benefits of BDD

2. Introducing BDD slowly

3. Offering proper training and resources

4. Celebrating early wins to create momentum.

You can use BDD testing effectively by:

Automating BDD tests improves the development process by offering immediate feedback about the system’s behavior and maintaining software quality.

You can measure the effectiveness of BDD testing by tracking metrics like:

• Defect rates
• Rework time
• Team velocity
• Stakeholder satisfaction

These metrics will help you improve your BDD testing over time.

BDD Testing Levels and Strategies

BDD testing takes place at three different levels:

• Story level: Highest business value

• Feature level: Specific functionality

• Scenario level: Concrete examples of behavior

You can use BDD testing effectively by:

• Writing scenarios before implementing the code
• Including all stakeholders when creating scenarios
• Regularly updating and reviewing scenarios
• Automating scenarios in the CI/CD pipeline

Real-world BDD Implementation Examples

There are case studies of successful BDD adoptions that prove its value. For example, one large financial institution saw a 30% reduction in defects after implementing BDD.

The key lessons learned from BDD adoptions are to:

• Start with a small group and scale from there
• Ensure you invest in training and the right tools
• Enforce consistency in BDD practices across teams
• Iteratively examine and improve your BDD approach

BDD has a major effect on the success of a project and the team’s productivity. Teams see increased collaboration, faster development cycles, and higher quality software.

The top best practices from real world experience are:

1. Group scenario writing sessions
2. Iteratively improving BDD processes
3. Combining BDD with how development is already done
4. Continuous improvement and learning of BDD skills.

To further enhance your BDD implementation, consider exploring agile tools that can support your team’s workflow and collaboration.

Final Thoughts

Behavior Driven Development is a game changer for software development. It improves communication, eliminates misunderstandings, and produces higher quality products.

BDD takes a collaborative approach that ensures everyone is on the same page with the same goals. I’ve implemented BDD in various projects, and it has always resulted in a more streamlined process and happy stakeholders. You can also apply the principles of BDD to things outside of software. It will change how you solve problems in many business and life scenarios.