Introduction to System Testing | What Is System Testing ?

System Testing Objective:

System testing is one of the most important processes in the development of software. It consists of an evaluation of the functionality and performance of the integrated software solution with corresponding requirements. This testing is done after integration testing and before acceptance testing.

System testing as a well-developed phase in software development is the examination of a fully integrated software product. It is conducted after integration testing and before acceptance testing and its purpose is to assess whether or not the system’s characteristics meet required specifications and whether the system functions properly when it is used in its intended context.

There are a lot of testing objectives, however, the main and evident goal is to ensure that entire system fulfills its specific purpose. This entails checking whether all sub–systems and sub–assemblies communicate as they should and undertake their various functions in the intended way. System testing that is also called final testing is conducted to find out other defects that were not exposed at integrated testing and check that the system works as per the specified standards.

Key Features of System Testing:

System testing is focused on whether the software meets the requirement and hence is fit for release or delivery to the customer. It utilizes components that have passed integration testing. The primary objective is to detect irregularities between the integrated units and the system as a whole, identifying defects at both levels. The results obtained from system testing provide insights into the observed behavior of the components or the entire system. It covers testing against system requirement specifications, functional requirement specifications, or both. It further looks at the system design, behavior, and customer expectations. It goes beyond the confines laid out in the software requirements specification (SRS). It is a specialized testing process performed by an independent testing team, ensuring an unbiased assessment of the quality of the system across the functional and non-functional aspects. It takes place after integration testing and prior to acceptance testing.

Types of System Testing:

One of the system tests that is used includes performance testing and checks on speed, scalability, stability, and reliability. They provide speed test results that gauge whether the system is able to handle a load efficiently, tests of stress that find out how robust a system can be when working on extreme loads. Scalability checks on system performance as a function of how many users the system is dealing with in load.

Here are some common types of system testing:

Functional Testing:

Objective: Ensure that the designed system works as expected and delivers good results.
Scope: Perform all unit/Integration/acceptance/sanity/Smoke/system level tests on all functional requirements and features of the system.
Example: Ensuring that a login feature enforces valid login inputs and disallows additional wrong login attempts to the application.

Performance Testing:

Objective: Determine how the system behaves in context to other conditions that can be designed and implemented.
Scope: It is recommended to evaluate the capability of the system in terms of its responsiveness to required changes, stability, and scalability.
Example: Evaluating the response time and system throughputs of an e-Commerce site under different bandwidth cultures.

Load Testing:

Objective: Learn how it performs with the attended load that is expected in normal circumstances.
Scope: Record metrics during high traffic to evaluate the response or conduct stress test with a large number of users/transactions.
Example: Checking accounts of a banking application where hundreds or thousands of users make transactions so fast.

Stress Testing:

Objective: Test for its response under optimal or worse conditions in other words test the robustness of the system.
Scope: Unleash the system to tunnel for failure points and to investigate why it slows down.
Example: Introducing load testing which is a process of creating a large number of transactions on a stock trading platform in an attempt to overwhelm the system and analyze its working under such conditions.

Security Testing:

Objective: Make sure no weaknesses are showing on the system and that no hackers are attacking it.
Scope: Perform stress tests for Authentication and Authorisation, Data protection and other areas of vulnerability.
Example: Conducting vulnerability assessment in an online banking system, with the aim of probing the system for its weak points.

Usability Testing:

Objective: Estimate friendliness of the system’s interface and usability of the system for the users.
Scope: Assess the extent based on which users are able to engage with the system with lots of convenience.
Example: Sitting with users to watch them while they surf a website in order to find out if there is anything that is complicated or difficult to use.

Compatibility Testing:

Objective: Make certain it runs in various environments and on diverse terminal equipment.
Scope: Verify your transmission on as many operating systems, browsers, and hardware platforms as you are able.
Example: Testing the working of a Mobile Application on various iOS and Android Operating System editions.

Regression Testing:

Objective: Ensure that the changes or updates made in the recent past have not misplaced new quality defects.
Scope: Repeat previous test cases that were previously passed to confirm that they are not distorted.
Example: Any new capability developed to transform a software application is followed by regression testing to verify that all the previously included features are still functioning as intended.

Recovery Testing:

Objective: Verify the recovery mechanism, and the system’s capability to come back to normal when it crashes, or falls or when certain undesirable conditions occur.
Scope: Introduce failures and test the ability of the system to self-heal or self-correct.
Example: how an application that uses a web-base operates when a database server either crashes or goes offline and then comes back online.

Installation Testing:

Objective: Check that software installations and removal are functional for a number of scenarios.
Scope: Check how the installation process will work, following the normal configuration and setup scenarios.
Example: Confirmation of integration of a software package in other operation systems, for them to check if they can install it smoothly.

Localization and Internationalization Testing:

Objective: Ensure the software functionality is perfect in all the languages and also all the regions.
Scope: Check the word translation issue, date and time conversion issue, issue of currency conversion etc.
Example: Conducting a cross-browser check for an e-commerce websites to see whether it returns the correct prices for different currencies.

Acceptance Testing:

Objective: Ensure compliance with the business needs of the enterprise and customer requirements.
Scope: Can be conducted by the end-users or the clients and is done to test whether the system has met the intended specifications.
Example: Performing UAT for a new CRM system to verify that it equips all the nail requirements of the business.

System testing is therefore an activity made up of several types of testing that assure the users and other stakeholders that a software system is indeed as good as it can get in terms of reliability and functionality and ready for use. Both of them emphasize on different aspects while giving a fairly inclusive assessment of the overall standard of the system involved.

Tools Used for System Testing:

Common system testing tools include:

JMeter
Gallen Framework
Selenium

In addition to the above, other tools in system testing include:

HP Quality Center/ALM
IBM Rational Quality Manager
Microsoft Test Manager
Appium
LoadRunner
Gatling
Apache JServ
SoapUI

Note: Tool selection is based on factors such as technology used, project size, budget, and testing requirements.

Advantages of System Testing:

Minimal knowledge of programming is required from the tester.
Determines whether the errors or defects are not caught during unit or integration testing.
Simulates actual production or business environments to carry out testing.
Ensures customer technical and business requirements are met.
Provides confidence during acceptance testing as the coverage for bugs or errors is provided.
Validates the functionality of the system early on in development.

Disadvantages of System Testing:

Despite its advantages, system testing presents with the following disadvantages:
Time-consuming process covering the entire software.
High testing cost for many software testing processes.
Robust debugging tools are dependent and have to unearth hidden errors.
Complexity and challenges that increase with larger systems.

System Testing Process:

Setting up a testing environment conducive to quality testing.
Development of comprehensive test cases that will be the driving force of the testing process.
Generation of test data required for testing purposes.
Execution of test cases using the generated test data.
Defect identification and reporting during testing.
Regression testing when defects or side effects occur from testing.
Defect resolution.
Retesting if the initial testing result is not successful.

The system testing process typically involves the following steps:

Test Planning: This step involves identifying and describing the system testing’s working scope, purpose, available resources, time line, as well as what is expected to be produced.
Test Case Development: Deriving test cases and test scripts with down to the last feature from the total requirements and specifications.
Test Environment Setup: All the preparations done prior to actually testing the hardware, software configurations, and the network settings and tools that would be required for the testing process.
Test Execution: To that end, the following activities were undertaken: Executing the test cases and logging the outcomes.
Defect Reporting and Tracking: Those areas that contain defects or which need to be checked for defects have to be recognized, recorded and monitored.
Test Closure: Coordinating and organizing testing, reviewing the results of tests, and giving a concluding test report.

Test Environment:

System testing is another black-box testing that involves testing the entire integrated software system; the testing environment should be as close as possible to that of the real environment such as the production environment. The specificity of the equipment, programs and databases that used in the QA environment should be similar to the production environment. This maintains consistency in its interaction with the environments it exists in. .

End-to-End Testing:

Immediate testing on the developed application follows its overall usability testing by clicking on all the functionality to check if they are in proper order. For example, when testing the application called WhatsApp, the tester has to install the application, to input a profile picture and send messages, and so on; this way overall, the typical functionality of the application is tested to ensure that it does meet the expected objectives of the end user.

Examples:

WhatsApp: Several examples of testing that the test engineers will be performing include applying different use cases of the application as a single user, sending message, uploading profile picture, and using all the application’s features.
Facebook: The basic tasks that are commonly performed with the help of the application are entering the application, looking for a specific person, possibility to send a message and exit.
Amazon: Registering as a new customer, entering a keyword to search for a product, selecting the required item, and proceeding through the check out options.

System integration tests assure end users that the software they are purchasing will work cohesively as a single application and performs as expected. This phase is important since it ensures that every integrated sub-systems of a system works well in a rehearsed environment.

Here's the reference video for you to watch and better understand the topic:

Conclusion:

In summary, system testing plays a key role in ensuring software reliability, functionality, and performance. Organizations who follow defined processes, effective use of tools, and work with dedicated testing teams can identify and fix problems early on in the development cycle, leading to quality software solutions.

A system test is a critical phase because it enables an assessment of the integrated system to ensure all the constituent elements combine well. It aids in detecting and eliminating defects even before the final product gets into the hands of the buyer hence minimizing failure cases and strengthening the standard and stability of the software.

In conclusion, it would be possible to state that the system testing plays a significant role of providing the end product that is fully functional, independent and free of any defects or bugs. The testing convinces you that the entire system is fully operational, compliant with the laid down standards and requirements, and ready for actual use in a real world setting.