Embedded Testing (Types of Embedded Testing, Differences between Embedded Testing and Software Testing

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Embedded Testing is a process to check the functional and non-functional factors in an embedded system. The testing ensures both software and hardware aspects of the system is fully functional and free from defect. Meaning, the product is all set for the final release. This testing is also conducted to see whether the product completely features all the client's requirements or not. The need for embedded testing is highly essential to ensure high-end security for applications related to industries like railways, vehicles, aviation, medical, banking, etc.

Types of Embedded Testing

Embedded software can be tested using five levels of testing processes

Software Unit Testing

In Software Unit testing, testers run the test on a software's units or components to see whether the code of each unit performs as expected. It is done during the software development phase by isolating a section of code and verifying its accuracy. A unit can be anything- function, module, object, procedure, and method.

Unit testing is mostly conducted under the leadership of a developer and then passed on to a peer-review model. Once specifications are set, the next step is to develop module test cases.

Integration Testing

You can further classify integration testing into two sections- Software integration testing and software/hardware integration testing.

It includes testing the interaction between software components and the hardware domain. You can also execute this test to analyze the interaction between software and built-in peripheral devices.

Embedded Testing are always run in a real environment similar to that of software. Since it's impossible to run comprehensive testing in a simulated condition, most testers find embedded testing a critical task.

System Unit Testing

The module developed for the test comprises a framework consisting of complete information about software codes, the real-time OS (RTOS), including details about communications, mechanisms, and interrupts, etc. From this point, the point of control protocol is utilized for sending a message and ensure it is utilized via the RTOS message queues.

Then the developer or the system integration team observes the system resources to analyze that the system can accommodate the embedded system execution. This process is often executed using gray box testing.

System Integration Testing

In this process, the entire system including subsystem components within a single node. A combination of network communication protocols and RTOS, including network messages and RTOS events, is used as the Control and Observations Points.

System Validation Testing

In this testing, testers ensure that the whole embedded system and subsystem are implemented perfectly. The main objective is to analyze whether the external entity can match the functional requirements of the product. An external entity can be either a person, a device, or both.

Difference between Software Testing and Embedded Testing

Software Testing is done to verify and validate the behavior of the developed product, ensuring the software is error-free and works as expected. Once confirmed, documentation is prepared to mention all requirements have been met.

Embedded Testing is conducted to verify and validate how the software and hardware behave when someone uses the product. This test confirms that the embedded system works perfectly without showing any bugs or glitches. It is also a yardstick to measure how well the software meets customer requirements and helps in finalizing the documentation process as well.

Key differences between Software Testing and Embedded Testing

Key factorsSoftware TestingEmbedded Testing
TargetSoftware testing is performed on client-server oriented applications and software.
Embedded testing is executed on both software and hardware.
TypeIt is generally based on black box testing.
It can be based on both white and black box testing.
TestingIt is used to test functional aspects of a software.
It is conducted to test the hardware behavior.
Area of applicationIt is used on web and mobile applications.
It is used on embedded systems.
CostIt is a costly and time consuming task.
It doesn’t take much time or cost.
ProcessIt can be operated both manually or automatic.
It is a manual process.

Challenges in Embedded Software Testing

Following are the challenges faced by software engineers in Embedded Testing

Dependency on Hardware

Embedded software is highly dependent on a hardware device that invites several technical challenges for the testing team. The likelihood of the unavailability of a competent hardware platform during the initial testing phase is quite high. Therefore, testers have to resort to carrying out the test without a system hardware platform. In such situations, testers have to settle with emulators and simulators, which don't represent the real behavior of an actual device. Hence, such things often lead to inaccuracy in determining the system's usability and performance.

High level of defects

Given that embedded testing is tested on both software and hardware, it is common to detect a high ratio of system defects. The problem is that it's hard to detect whether the defects are mostly concentrated on the part of software or hardware or both. This makes the debugging process even more complex. Besides, the testing team's need for hardware and software knowledge is quite essential in such cases. On top of that, the embedded software works great on one hardware variant, meanwhile shows errors on another hardware. This is also a big obstacle that is often faced during the embedded testing process.

Reproducing a bug or defect is challenging

Reproduction of events happens in software and hardware; it makes it even more complicated to reproduce defects in embedded testing. Meaning, testers have to analyze every defect at a higher level. Since finding the source of defects is also a pain, it is also harder to gather reproduction data analysis.

Frequent upgrades are needed

An embedded system must go through frequent upgrades such as security fixes, RTOS upgrades, kernel upgrades, and many more. Such changes can directly impact the testing activities, making them more complex. Therefore, extra care is taken during the build, production, and deployment process.

Test Automation

Test automation can be a real headache while conducting embedded testing, given it is highly dependent on hardware and hardware interfaces. Therefore, developers or testing engineers need to develop test rigs that support both software and hardware automation.


Executing embedded testing is harder than regular software testing since it heavily relies simultaneously on hardware and software. Therefore, testers should opt for automated software testing using custom tools. Embedded testing can be complicated, but one can complete it within hours using the right skill set and tools.

Updated on 17-Aug-2021 14:59:55