System Testing vs. End-to-End Testing

Anushree Chatterjee

Remember building sand castles at the beach? You meticulously sculpt each tower, dig deep moats, and decorate with seashells – that’s your system. You’d check if all these parts are holding well and working together, that is, making sure that each part is perfect.

But will it withstand the tide? Will the drawbridge actually lift when the little plastic knight comes charging? Now, you’re thinking from the end user’s perspective. You look at the system beyond the controlled construction environment by taking a step back to see the whole beach. You’d want to try out different scenarios that your user (that is you) would like your castle to do well, like withstand the crashing waves and the knight’s grand adventure. All this to make sure your sandcastle, in all its glory, can handle the real world.

Of the many types of software testing techniques, system testing, and end-to-end testing are often confused and used interchangeably. Even though they do differ from one another.

Let’s understand these types of testing better.

What is System Testing?

Imagine you’re putting together a puzzle. Where each piece represents a different part of your system, like the database, the user interface, and the backend services. System testing is when you make sure all the pieces fit together properly, and everything is working as it should.

For example, if your software interacts with other systems, like payment gateways or third-party services, this is the time to check if everything integrates well. It helps identify bugs that might have been missed earlier when individual parts of the software were tested separately.

What is End-to-end Testing?

End-to-end testing is like simulating a real-life experience of using your software from start to finish, just as an actual user would. It involves testing the entire system to make sure everything works together smoothly, exactly how it’s supposed to, across all its components, including external systems or services it might interact with.

Imagine you have an online shopping app. In end-to-end testing, you wouldn’t just test the shopping cart feature or the payment system in isolation. Instead, you would test the whole process, from when a user first opens the app, browses through products, adds items to the cart, proceeds to checkout, makes a payment, and receives a confirmation message. You would test everything in between, like making sure the inventory updates when an item is sold, the payment system communicates correctly with the bank, and the shipping information is sent to the delivery service.

Difference Between System Testing and End-to-End Testing

Do both these forms of testing seem quite similar to you? Well, they are similar in the sense that they both concern themselves with the system once it is assembled as a whole. They both check if the different components of the system work well together.

But that’s an amateur’s view on these two types of testing. If you look closely, you’ll see the nuances that make these two distinctly different. Let’s take a closer look.

Let’s talk about the scope of these two.

• System Testing: Here, you are testing the entire system as a whole, but you focus on how each part (or component) of the software functions. You might test things like the database, user interface, and server separately to make sure everything is working correctly in isolation.
• End-to-end Testing: End-to-end testing, on the other hand, tests the whole software system as a complete workflow, from the start to the finish, just as a user would experience it. For example, in a shopping website, you would check if a user can browse products, add items to the cart, make a payment, and receive a confirmation email.

If you look at the focus of these two different forms of testing, you will see the difference.

• System Testing: The focus here is on verifying that all the internal components of the system (like individual features, modules, or functions) work as expected. For instance, does the login page allow users to enter their credentials and access the system? Does the database return the right data when queried?
• End-to-end Testing: This type of testing is more about making sure that the entire user journey works as expected across different systems or services. It simulates real-world scenarios to check if everything integrates properly. Usually this is all in one continuous flow.

Each of these types of testing differs with respect to the environments in which they are performed.

• System Testing: Here, you usually perform tests in an isolated environment that closely mimics the real-world setup. However, it may not involve actual user interactions or external systems (like third-party services or databases). The focus is on the software’s internal workings.
• End-to-end Testing: In end-to-end testing, you test the software in an environment that is closer to the real world, where all external systems and integrations are involved. It tests how the software works with other systems or services it depends on.

Both these testing types take up different amounts of time and add complexity.

• System Testing: This usually takes relatively less time because it focuses on individual components, testing their functionality. It is relatively less complex because you are testing the parts without involving complex real-world scenarios.
• End-to-end Testing: This takes more time and is generally more complex because it tests the entire workflow. This requires you to test many different scenarios from the user’s point of view. You might also need to set up external systems or services to simulate real-life conditions, which makes it more time-consuming.

While both these types of testing are great, they serve different purposes and knowing when to use them is important.

• System Testing: Use this to check your system after a successful integration testing and right before you hand over the system to the user for acceptance testing. This type of testing is good to cover non-functional requirements of performance, security, reliability, usability, and compatibility.
• End-to-end Testing: End-to-end testing typically builds over system testing. You need a well-functioning system, which system testing gives you. With a shifted focus on user workflows, you can verify critical user journeys, which inevitably exercise different components of the system.

System Testing vs. End-to-end Testing

Here’s a brief tabular view of the two types of testing.

Automating System Testing and End-to-End Testing

Despite the differences in both these types of testing, the thing that is common is that you need to test various aspects of the application. And we all know that to do this, making use of test automation is the best way ahead. To get even better results from your test automation endeavors, make use of generative AI-powered tools like testRigor.

testRigor uses generative AI to make test automation easy for everyone. It is a cloud-based solution that lets you automate a variety of test scenarios across different platforms and browsers effortlessly. Here’s how.

• Anyone can create tests: testRigor uses generative AI to let users create test cases in simple English language. No caveats! So you need not worry about those problematic XPaths or CSS values that keep changing with every release. Just write what you see, and testRigor will do the rest. In fact, you can skip this, too, by using the generative AI feature to create test cases. Here’s a detailed guide that tells about the different ways, each simpler than the other, to create tests in testRigor: All-Inclusive Guide to Test Case Creation in testRigor.
• Negligible test maintenance: testRigor makes use of AI to self-heal tests and prevent flakey runs. This saves a lot of time and effort. Read more about this over here: Decrease Test Maintenance Time by 99.5% with testRigor.
• Easy integrations: You can integrate testRigor with your existing CI/CD or test case management systems to make sure that all your test cases are being run as desired. This is helpful when you want to run test suites after important system releases.

There’s a lot more you can do with testRigor. Take a look at the tool’s offerings over here – testRigor’s features.

Conclusion

Rather than looking at system testing and end-to-end testing as completely different techniques, think of them as complementing each other. Through system testing, you can make sure that whatever you integrated and built separately is now a whole unit. While doing so, you can even check various other aspects of the system, like performance, security, and usability. Once you’ve vetted the system, you can use end-to-end testing to check for those specific user workflows that you know your system will be used for. Thus, using these two techniques together will help you thoroughly test your application.

“We spent so much time on maintenance when using Selenium, and we spend nearly zero time with maintenance using testRigor.”

Keith Powe VP Of Engineering - IDT