Types of Software Testing
There are many approaches, each checking a different aspect. Let's review the main types.
Functional Testing
Checks compliance with functional requirements: whether the system correctly performs functions under different conditions.
Non-Functional Testing
Evaluates performance, security, usability and compatibility. For example, load testing or security testing to identify vulnerabilities.
Unit Testing
Tests components or modules separately. Allows detecting errors early and facilitates debugging.
Integration Testing
Tests interaction between modules/systems, to identify errors in combination and ensure joint operation.
System Testing
Tests the entire system against requirements, how all components work together and whether it meets user expectations.
Acceptance Testing
Confirms that the software meets client requirements and is ready for launch: business logic, functionality and usability.
How to Choose the Right Testing Model
Choosing the model depends on the development stage, requirements, scope, timelines, resources and methodology. Let's examine applicability and criteria.
1. Development Stage
• Early stage → Unit testing to identify code errors.
• After component integration → Integration testing examines interaction.
• Before launch → System testing to identify system-level defects.
• Before delivery to client → Acceptance testing confirms readiness.
2. Project Scope
• Small project → Unit + integration are sufficient.
• Medium project → Add system testing.
• Large project → All levels, including alpha/beta.
3. System Criticality
• High criticality (healthcare/finance) → Multi-layered: unit, integration, system, acceptance.
• Medium criticality (business applications, SaaS) → Integration + system.
• Low criticality (prototypes, early startups) → Unit and partial integration.
4. Time and Resource Constraints
• Short timelines → Automate unit and integration.
• Lots of time/resources → Full coverage of all types.
Selection is influenced by the project, and in practice several types of testing are combined. Unit early, integration for interactions, system for the entire product and acceptance for final approval.
Software testing is critical for quality and reliability. Correct selection, understanding of testing types and process stages enables efficient detection and fixing of defects, creating products that meet user requirements and ensure satisfaction.
