System Testing plays a crucial role in software development, as it ensures the validation of a fully integrated software product. This level of testing focuses on evaluating the end-to-end system specifications. In most cases, the software is just one component of a larger computer-based system, where it interfaces with other software and hardware systems. System Testing involves a series of diverse tests that aim to thoroughly exercise the entire computer-based system.
What is System Testing?
System Testing is a comprehensive testing process that evaluates the complete software system, including its interfaces with external components such as hardware, databases, networks, and other software systems. The primary objective of System Testing is to verify whether the software system meets the specified requirements and functions correctly in a real-world environment.
System Testing involves testing the software code to verify the following:
- Testing the fully integrated applications, including external peripherals, to assess how components interact with one another and with the overall system. This is also referred to as End-to-End testing scenarios.
- Ensuring thorough testing of every input in the application to validate the desired outputs.
- Evaluating the user's experience with the application.
The above description provides a basic understanding of what is involved in system testing. To delve deeper, it is necessary to create detailed test cases and test suites that cover each aspect of the application from an external perspective, without examining the actual source code. For a comprehensive approach to this process, consider exploring end-to-end testing methodologies, including reviewing our article on Black Box vs. White Box Testing.
Software Testing Hierarchy
Similar to many software engineering processes, software testing follows a prescribed order. The following list outlines the chronological order of software testing categories, which are undertaken to thoroughly test new software before its release:
- Unit Testing
Conducted on each module or block of code during development. Typically performed by the programmer responsible for writing the code.
- Integration Testing
Performed before, during, and after integrating a new module into the main software package. This involves testing each individual code module to ensure their effects on the entire program model.
- System Testing
Carried out by professional testing agents on the completed software product before it is introduced to the market.
- Acceptance Testing
Beta testing of the product performed by actual end-users.
Types of System Testing
The world of system testing comprises a wide array of over 50 different types, and the specific testing methodologies employed by testers depend on various factors. These factors play a critical role in determining the types of system testing suitable for a particular software project. Let's explore some of the key variables that influence the selection of system testing types:
- Organisation Size and Context
The type of organisation for which the tester works is a major determinant in choosing the appropriate system testing types. Testing methods utilised by large companies differ from those employed by medium-sized and small companies. The scale, complexity, and specific requirements of the organisation's projects influence the testing approaches adopted.
- Time Constraints
While there is a rich variety of testing types available, the time available for testing is a limiting factor. Ideally, all 50 testing types could be utilised, but practical considerations often require testers to focus on the types most relevant to the software project at hand. Time constraints necessitate prioritisation and selection of the most impactful testing methodologies.
- Available Resources
Testers may encounter limitations in terms of resources required to conduct certain testing types. For instance, expensive automated testing software may be available to testers working in large software development firms but may not be accessible to others due to budget constraints. The availability of tools, equipment, testing environments, and skilled personnel can significantly impact the selection of system testing types.
- Tester's Skill and Education
Each type of software testing has its own learning curve, and testers need to acquire the necessary knowledge and expertise to effectively employ different methodologies. Testers must possess the required skill set and understanding to utilize specific software testing tools and techniques. The tester's education, training, and experience play a vital role in determining the testing types they can proficiently employ.
- Testing Budget
Budget considerations influence the selection of system testing types across organisations, not just for smaller companies and individual developers but also for large enterprises. Financial constraints may limit the allocation of resources to specific testing types. Organisations need to prioritise their testing activities based on available budgets and ensure the most critical testing needs are addressed effectively.
By taking these variables into account, testers can make informed decisions about which system testing types to employ. It is essential to strike a balance between the available resources, project requirements, time constraints, and the organisation's context to ensure comprehensive and effective system testing that aligns with the specific goals and constraints of the software project.
Types of System Testing
Although you can find exhaustive lists on the internet, it's not necessary for what is actually employed in most real-world scenarios and as such, we will focus on the types that are typically employed by large software development companies:
- Usability Testing
Emphasises the user's ease of using the application, flexibility in handling controls, and the system's ability to achieve its objectives.
- Load Testing
Essential for determining how a software solution performs under real-life loads.
- Regression Testing
Ensures that changes made during the development process do not introduce new bugs or reactivate previously resolved issues resulting from the addition of new software modules over time.
- Recovery Testing
Demonstrates that a software solution is reliable, trustworthy, and capable of successfully recovering from possible crashes.
- Migration Testing
Ensures seamless transition of the software from older system infrastructures to current system infrastructures without any issues.
- Functional Testing
Also known as functional completeness testing, it involves identifying any possible missing functions and suggesting additional functionalities to improve the product.
- Hardware/Software Testing
Also referred to as "HW/SW Testing" by IBM, this type of testing focuses on the interactions between hardware and software during system testing.
System Testing is an essential phase in software development that verifies the integrity, functionality, and performance of a fully integrated software system. By conducting thorough and comprehensive system testing, organisations can identify and rectify issues before releasing the software to end-users, ensuring a high-quality and reliable product. By utilising appropriate testing methodologies, system testers can contribute significantly to the success of software projects by delivering robust and user-friendly systems.
