What Is End-to-End Testing? A Complete Guide

Your business needs optimized systems and cutting-edge tech to stay ahead of the competition. To acquire these, you must leverage end-to-end testing frameworks and thoroughly assess the performance of your core business applications.

But what exactly is end-to-end testing, or “E2E,” as it’s often called? More importantly, how does it fit into your overall business optimization strategy?

This guide will familiarize you with end-to-end testing tools, concepts, and frameworks you can use to revolutionize your operations. We’ll also provide end-to-end testing examples and actionable steps for implementing an E2E strategy.

Defining end-to-end testing

End-to-end testing is a software testing methodology that ensures your applications function as anticipated. E2E testing also allows you to map the flow of data across on-premises applications and web services. It can involve manual or automated testing.

As the name suggests, E2E testing begins from the end user’s perspective and emulates a real-world situation. By simulating such a scenario, E2E testing verifies that all actions within the workflow function as the user would expect.

Although end-to-end testing is a vital component of a thorough testing strategy, you’ll need to perform other assessments to maximize the efficacy of your tech stack, such as ETL testing, enterprise service bus (ESB) testing, and integration testing.

End-to-end testing versus integration testing

Integration testing is performed before rolling out a new technology. Its purpose is to ensure an application’s various components work together.

Integration testing doesn’t analyze the functionality of an application from the end-user’s perspective. As such, an app may pass integration testing even if it has disruptions in data flow or provides a clunky user experience.

By contrast, end-to-end testing is conducted from the end user’s perspective to ensure they enjoy a consistent, frictionless experience. The scope of E2E testing is much broader, providing more relevant insights into an app’s performance and usability.

However, the broader scope of E2E testing for web applications also drives up the cost.

Types of end-to-end testing

There are two basic types of end-to-end testing: vertical testing and horizontal testing.

Vertical E2E testing

Vertical E2E testing is the more technical approach to software development and manual or automated testing.

When performing vertical E2E testing, developers start from the end-user's perspective within the user interface (UI). However, they’ll also interact with the backend of the tech stack to ensure that data is routed to the correct location. Each phase of the test occurs in a sequential order that mimics the actual flow of data.

Horizontal E2E testing

Horizontal end-to-end testing focuses on verifying the proper function of each workflow within an application.

QA testers put themselves in the end user’s seat, using the UI when constructing and performing the test. They don’t interact with the backend, instead assuming data is routed to the correct location if the app functions correctly on the front end. 

End-to-end testing: benefits and challenges

Whether running on-premises or cloud-based applications, you must perform E2E testing. Doing so provides many benefits, including improved app performance and a better ROI. That said, certain challenges can make E2E testing difficult.

Let’s take a closer look at some of the benefits, as well as a few potential challenges you may face when adopting end-to-end testing frameworks.

Benefits

End-to-end testing provides the following benefits:

• Enhances test coverage: E2E testing is one of the most thorough testing frameworks. It lets businesses make a holistic assessment of app performance. They can use these insights to improve productivity and address deficiencies within their technology stack.
• Validates application performance: E2E testing also enables the QA team to validate application performance from the end-user's perspective. They can effectively “see” what end users experience while using an app and determine whether the UX lends itself to optimal productivity. 
• Improves the user experience: E2E testing empowers the QA team to create an optimized UX. This, in turn, reduces friction for users and increases your app’s adoption and retention.
• Ensures consistent app quality: End-to-end testing ensures the front end of an application works as intended. During E2E testing, QA personnel can gauge app performance across various platforms, devices, and browsers to ensure a consistent experience. 

Challenges

Although E2E testing provides distinct benefits, testers must overcome a few hurdles to implement an effective end-to-end testing strategy. Here are some typical obstacles:

• Time-consuming: Due to the complexity of E2E testing frameworks, these application assessments take time and effort to create. As a result, some organizations focus on testing strategies with a narrower scope. 
• Difficult to set up: QA personnel must understand users’ goals to set up an insightful end-to-end test. Stepping into the end users' shoes can be challenging, especially when an organization employs a third-party QA team. 
• Costly: Running E2E tests may require expensive hardware or software tools. This further discourages some organizations from engaging in this type of testing.

Despite these challenges, E2E testing remains one of the most pragmatic means of optimizing app function and enhancing the user experience. 

How to implement end-to-end testing

Typically, end-to-end testing involves seven key steps:

1. Decide how to evaluate E2E testing results.
2. Set up test requirements and environments.
3. Define the processes of the system you’re testing.
4. Describe the roles and responsibilities of each system and subsystem.
5. Identify your testing tools and framework.
6. Set requirements for designing test cases.
7. List the input and expected output data for each system involved in the test.

By following these steps, you can implement your own E2E testing strategy and better understand the end-user experience.

End-to-end metrics to measure results

There are many ways to measure the results of your E2E tests, but the following are among the most commonly used metrics:

• Test case preparation: This metric monitors the test cases that are still being prepared compared to those you’ve already planned.
• Test progress tracking: Tracks the progress of your tests on a weekly basis; you should monitor the progress of each test using clear terms, such as valid/invalid or pass/fail.
• Defect details: This is a list of weekly defect distributions based on priority and severity.
• Test environment availability: This metric outlines the number of daily testing hours.

These metrics will help you monitor your testing program more effectively and confirm it produces actionable insights about application performance and UX. 

End-to-end testing example

To get a better idea of what E2E testing looks like in action, consider the following example.

Imagine you’re a retailer who wants to verify your platform communicates with your distributor’s software. More specifically, you want to know if your software is sending incoming order information to the distributor so they can prepare it for shipping. End-to-end testing can confirm whether your electronic data interchange (EDI) software effectively sends and receives data.

In this case, your E2E test could involve:

• Verifying the functions on your order submission page
• Tracing the data to ensure it’s promptly delivered to the distributor’s order management technology
• Validating they’re notified of the new order request

Learn more about E2E testing

If you want peace of mind that your data is accurately transmitted, received, processed, and validated according to best practices, Orderful can help. Speak with one of our EDI experts to learn more about Orderful’s revolutionary EDI technology.