Quality maintenance (QM) is a method for building in quality and preventing quality defects through the process and through the equipment. In quality maintenance, variability in a product quality characteristic is controlled by con- trolling the condition of equipment components that affect it. Quality characteristics‘ are mainly influenced by the four production inputs: equipment, materials, people’s actions (skills), and methods used. The first step in quality maintenance is to clarify the relationships between these factors and a product’s quality characteristics by analyzing quality defects.
In process industries, the effect of equipment on quality characteristics is particularly important. In process industries, the process determines the type of equipment needed. Therefore, teams should focus first on the process, then on the equipment. In other words, first clarify the relationships between product quality and process conditions and ascertain the precise process conditions required for producing perfect product. Equipment is a means of implementing a process. Therefore, applying a
QM approach in equipment design, teams begin by identifying the components that will affect the product’s quality characteristics. These are called “quality components.” Next, they pinpoint the quality component conditions required to maintain the quality characteristics. Quality maintenance used in this way assures quality at the very beginning of the production process.