Quality control has a significant role in engineering manufacturing processes. It is performed at various levels of industrial processes, such as sheet metal working. These levels include, designing, prototyping, testing, manufacturing, and production. Quality control is practiced to maintain a critical quality of products on the basis of several criteria, such as, functionality, consistency in design tolerance, work piece finish, and over strength and endurance. Mathematical tools and computer programs have been implemented in the process of quality control to make the process accurate, recordable, and efficient, which can also be retrieved for future reference.
Some of the significant methods of quality control, used in the manufacturing of sheet metal components are:
Total Quality Control (TQC)
It is employed in cases, where sales of a product decrease even after extensive use of statistical quality control. It may happen due to the exclusion of factors such as, customer's choice, reliability, safety, and maintainability. TQC performs refinement process by achieving parameters such as “Suitability for Purpose” and “Awareness for Quality” .
Statistical Process Control (SPC)
It is a graphical tool, which uses control charts to monitor process center, and process variation about it. Control chart, Shewhart chart or process behavior chart is a graphical tool used to determine the state of statistical controllability for any manufacturing process. SPC involves collection of data at various levels of manufacturing, using random sampling (in general). The control chart represents this data in the form of points, plotted against time or various stages of manufacturing processes. The control charts are plotted with a central horizontal line, which represents the mean process deviation. Any process can be set with an upper control limit and a lower control limit, defined by the maximum tolerances allowed in the manufacturing of any particular component. The motive of any manufacturing process is to bring the quality of all the finalized products between the upper control limit and the lower control limit, which is called the 6-sigma zone.
Computer-aided Quality Control:
The technology uses Computer-aided System Validation (CSV), which is to ensure that the system under consideration, works as programmed or designed, and perform it in a consistent and reproducible manner. CSV requires documented systems, as they clearly specify the intended use of a computer system application. The system requirements are collected and documented, while defining a system.
