Reliability testing is conducted to evaluate whether a product can maintain its functional reliability under all expected environmental conditions—including use, transportation, and storage—throughout its specified service life. It involves exposing the product to natural or artificial environmental conditions to assess its performance under actual use, transportation, and storage environments, and to analyze the extent and mechanisms of environmental impacts. By using various environmental test chambers to simulate climatic conditions such as high temperature, low temperature, high temperature and humidity, and temperature cycling, the tests accelerate the product's response to in-service conditions, verifying whether it meets the quality targets set during R&D, design, and manufacturing. This overall assessment determines the product's reliability lifespan.