[This post was originally written for TechTownTraining blog. You can find the original article here]
Automation testing is the application of tools and technology to testing software with the goal of reducing testing efforts, delivering capability faster and more affordably. It helps in building better quality software with less effort.
Many companies are already using automation testing to a certain extent, but still largely depend on manual tests because they don’t know how to properly leverage the benefits of automated testing in their development process.
Manual testing is performed by carefully executing predefined test cases, comparing the results to the expected behavior and recording the results. Manual tests are repeated each time the source code changes and is prone to errors. It is also difficult to execute on multiple platforms.
It is necessary to invest significant time and effort when introducing automated tests in an organization. However, there isn’t much of a financial commitment, at least not while starting out on a small scale. There are numerous open source test automation tools that could be made use of, especially in the early stages.
Usually, companies whose main product(s) is not software are afraid to invest in automation testing fearing that the returns won’t be as expected or if there will be a positive ROI at all.
In the rest of the article, let’s have a look at why automation testing is necessary for your organization and the benefits it can bring.
Reduce Cost (Of Failure)
As touched upon earlier, the initial cost of starting out with test automation is not too high. But once your organization is truly up and running with the idea of test automation, you would want to invest in better tools, better servers, hire resources to maintain the infrastructure etc. These costs are definitely not insignificant.
The automated tests aren’t going to write itself. Creating automated tests that are valuable takes human time and effort, and it won’t happen overnight.
If you want to justify introducing automated tests, don’t just look at the financials, instead look at the cost of failure. What does it cost the company if problems are not found while manually testing and escape into production? Do you stand to lose customers? How much in time, resources and money need to be spent rectifying the situation?
A really strong set of test-suites that are executed repeatedly each time a change is made to the code reduces the risk of issues leaking into the field. Automated tests helps in finding bugs early in the software development lifecycle, thereby reducing the risk of delivering faulty software.
At the end of the day, delivering a quality product to the market beats any other type of savings and cutbacks.
While the initial setup of automated test cases take a lot of time and effort, once you’ve automated your tests, you can reuse these tests. Automated tests can be executed significantly faster than manual tests, are less error prone and less labor intensive.
In a constantly changing code base, you have the ability to automatically execute the tests on each commit. You won’t have to continuously carry out manual steps by setting up the environment or remember the steps to execute each test. Everything is done automatically.
Once the setup is in place, automated tests can be repeatedly run, reducing the time to run repetitive manual tests from weeks to hours.
Once written, the tests can be executed any number of times with no additional cost. The tests are also available 24/7, unlike manual testers!
It is a common practice in software development teams to run basic unit tests many times a day (usually for each commit) and larger and time consuming integration and UI tests a few times a day (usually after office hours).
Foundation for CI and DevOps
Automated tests form the basis of any Continuous Integration or a DevOps setup. Essentially, both CI and DevOps depend on the philosophy of “Fail fast, Fail early”. Every commit to the code base is to be tested automatically and the results reported back to the developers. The developers prioritize fixing any of the tests that have broken the build ensuring that the mainline code is always working as expected.
You can read more about how automated tests play a significant role in Continuous Integration in the post Continuous Integration Part 1: The Fundamentals
Accuracy and Reliability
Manual testing is prone to errors because of the number of prerequisites involved in running each test. Additionally, each test may require a different execution sequence.
Manually testers are humans after all, so mistakes are to be expected. This may result in inaccurate results being propagated to the development team.
Automated tests carry out the same steps every time, with precision. The results are generally made available to everyone concerned in the least possible amount of time.
Yet another aspect of reliability is to re-execute the same tests on different servers. This gives the ability to quickly verify whether the tests are running as expected on all servers, thereby ruling out the possibility of server configuration issues.
Load testing ensures that your application can handle expected and unexpected user loads.
If you are currently using a manual testing approach in your organization, the load testing is probably pushed off until the end of a development cycle. While Agile methodologies and Continuous Integration make the case for load testing early and often, a large percentage of organizations continue to perform these too late, ultimately resulting in release dates pushed further and delayed software releases.
Automated testing is capable of running thousands of tests simultaneously, simulating millions of users, all of which is next to impossible with manual testing.
Realistic load tests must include parameterized settings that are configurable using variables that are randomized and represent what happens in the real world.
Agile methodologies recommend short cycles of feature development, called Sprints that usually run for 2-3 weeks. These short sprints are repeated within a bigger release lifecycle.
This calls for a new way to organize the test efforts and demands greater efficiency.
Each sprint is focused on development of a small set of features, but must deliver a functional system at its end, including all features from the previous sprints.
Without proper testing, the risk of delivering a full functional system without breaking a previously working feature is high. Manually testing all features again and again in every sprint sprint is counter-productive, expensive and inefficient.
This is where test automation has it’s highest benefit. Automating the tests and being able to repeat it quickly in each sprint gives a confidence that all things are working as expected.
For more tips and best practices, refer to Continuous Integration Part 3: Best Practices
Measure Quality Metrics
Extensions and tools available for automated testing provide features to measure a number of code quality metrics such as code coverage (i.e. percentage of code that is actually tested), technical debt, code semantics check etc.
Usually, these measurements happen when the tests are executed as a part of a Continuous Integration setup or a DevOps workflow.
For more details on this topic, refer to the post Continuous Integration Part 2: CI Server & Toolkit
They are able to measure such metrics because the tests themselves co-exist with the rest of the code. This provides opportunities to measure quality of huge code bases in a matter of minutes by parsing the source code during an automated build phase. This is not at all possible in manual testing.
If quality of your product is your number one priority, I strongly advocate using automation testing as part of your regular day-to-day development practices. It will ensure that your application is tested properly and gives confidence to developers, management and customer alike.
Automated tests have an upfront cost and they do take time to develop. The investment will pay off in the long term, in terms of reduced workload, eliminating manual errors, accuracy and savings on cost and time.
Overall, automated testing is a faster way to get feedback on failures than manual testing, inline with the principles of “Fail fast, Fail early”. It helps to ensure quality in a way manual testing never will be able to.