Discover how HIL testing enables early system-level validation of embedded software, even before it can be integrated with the physical environment or external systems.

Software-in-the-Loop (SIL) testing – A testing method where embedded software runs on a host computer instead of the target hardware, while interacting with a simulated environment. This enables functional validation and debugging early in development, before hardware or prototypes are available. Examples: Running a virtual model of an automotive ECU on a laptop to test control logic; simulating IoT device software before physical sensors are built. For testers: SIL provides fast, low-cost feedback during early development. It helps refine test logic and catch functional issues before moving to more expensive Hardware-in-the-Loop setups.

Hardware-in-the-Loop (HIL) testing – A real-time testing method where embedded software runs on the target hardware while interacting with a simulated environment that reproduces real-world signals and behavior. This enables system-level validation before physical prototypes are available. Examples: Testing automotive control software using simulated road and sensor conditions; validating a smart thermostat by simulating temperature changes and cloud responses. For testers: HIL allows safe and repeatable testing of edge cases, failures, and safety-critical scenarios. It can be resource-intensive, so plan which tests need HIL and which can run in virtualized environments.

Internet of Things (IoT) – A network of physical devices embedded with sensors, software, and connectivity that allows them to collect, exchange, and act on data over the internet or other communication networks. Examples include smart home devices, connected cars, and industrial sensors. For testers, IoT systems introduce challenges such as validating data accuracy, handling unreliable networks, ensuring security, and testing across diverse hardware and environments.