Regression and Reliability Testing

In General, testing is a set of activities which are performed on a hardware to identify the defects and evaluate the quality of the test object. Here, the functionality of the test object is checked against the requirements. Regression testing and Reliability testing are the fundamental testing performed on hardware before releasing it to the end user.

Regression Testing

This testing is performed when some changes has been made on the test object. The very purpose of this testing is to verifies that no adverse consequences has caused by the change/upgrade made in the hardware. To put it simply, the change/upgrade in the hardware has not reduced its performance from current state. Regression testing can be applied for both functional and non functional aspects of the hardware.

Functional Testing

In this testing, the hardware's function is tested for its conformance with requirement and specification. For instance, I have a machine which can measure blood pressure and the requirement is it should measure systolic pressure, diastolic pressure and the mean. In functional testing, these three functional requirements are tested. It address the following questions

What the product does? and What's the customer requirement?

Non-Functional Testing

In this testing, all the non functional attributes of the hardware are tested like usability, performance, maintenance etc. For Instance, the BP measuring device shall be compact, should have high accuracy and should have long battery life. Here, compact, accuracy and battery capacity are the non functional attributes which will be tested. It address the following questions

How the product perform? and What's the customer's expectation?

Reliability Testing

As the name states, the reliability (durability to repeated long term usage) of the hardware is tested. This test will be performed on several units on cyclic conditions until each unit fails. A meticulous failure analysis performed on those failed units and the design is tweaked until the design meets the robustness criteria which was defined by the manufacturer.

To wrap up, regression and reliability testing are the fundamental hardware testing which is critical for every hardware before releasing it to the user.