Survey report, also known as "cargo damage inspection report", is an objective written certificate issued by the inspection organization after the inspection of the damaged goods at the request of the inspector. In international trade, independent surveyors with credit, authority and aloof stand are often entrusted to inspect the extent and identification of damaged goods. The quality inspection before the sale of products and the statistics of the qualified number of the company's products are the written proof of identifying the product quality reaching the standard. It is obtained through the quality inspection of products and equipment, and is the standard to ensure the product quality system.

According to the applicability, the conclusions can be divided into two categories: 1. The test samples are provided by the enterprise, so the conclusion is only valid for the samples. 2. Inspection is for a certain batch of products, using sampling by attributes or percentage sampling. Therefore, the test conclusion is valid for the batch of products. Therefore, the test report only indicates the date of issue, and does not indicate the validity period of the report. For the test report of sample delivery, as long as the product design, raw materials and components used by the product are not changed, the test results should be valid; for the sampling test report of batch products, the report is valid once. When the relevant quality supervision department mentioned the validity of the test report, it may be to question the consistency between the product and the original test sample, or whether the consistency can be maintained for a long time. In fact, it is almost impossible for a product, especially for electronic and electrical products, to remain unchanged for several years, especially the suppliers of raw materials and components. Therefore, in theory, the test report has no validity period, but in practice, it is impossible to maintain the long-term validity of the test report for various reasons. The product certification certificate issued according to the test report has a valid period, which is because the product certification not only involves the design of the product, but also includes the quality management of the enterprise. Therefore, the validity period of the certificate is usually four years for the supervision once a year. Certificate expiration means that the test report issued for this certification is invalid. Therefore, the current national and international technical regulations do not stipulate the validity period of the test report. In order to standardize the mutual recognition of test reports by certification bodies in various countries and improve the validity of the reports, the international certification organization (iecee-cb) suggests that samples should be submitted for recheck if the test reports are valid for more than three years or modified more than three times.