Quality is the degree to which a set of inherent characteristics meets the requirements, including product quality and the quality of processes and systems. The inherent characteristics of product quality include the performance characteristics, special characteristics, economy, timeliness, adaptability and so on.
Reliability, serviceability, testability, security and safety constitute the specific characteristics of the product, which together with the performance characteristics of the product determine the effectiveness of the product.
Product effectiveness is the degree to which a product meets a specific set of task requirements under specified conditions and within a specified time. Economy refers to the total cost of obtaining and maintaining the operation of the product over its lifetime; Time refers to the delivery of the product on time, it also affects the life cycle cost of the product (the time of the cost); Adaptability reflects the product’s ability to meet market needs. The maximization of performance is achieved by weighing the cost of the life cycle, or the minimization of the cost of the life cycle is sought under the premise of realizing the cost of the life cycle.
While clarifying the relationship between product quality and product reliability, we should further distinguish between product quality problems and reliability problems in order to adopt different solutions to different problems.
In the process of product development, the quality questions that occur are usually divided into two categories, one is performance problems, if the units that make up the product do not meet the required performance indicators under normal working conditions, it is certainly a performance problem.
In addition, due to the product’s unit design is not coordinated, design parameters do not match and other reasons in the test caused product failure or damage, resulting in the product can not meet the specified performance targets, is also a performance problem, such problems should be resolved through performance design. The other is reliability.
Reliability is a measure of the sustainability of a product’s full performance requirements and a function of time. After the performance of the product has been tested and verified, the product with the technical status in the continuous work or not working state, due to the failure or failure of the units that make up the product, resulting in the product can not meet the required functions or performance indicators, is a reliability problem, should be improved by using reliability design methods.