Statistical Process Control of assembly lines in a manufacturing plant: Process Capability assessment

Among the main strategies adopted by companies for enhancing their competitive advantage as well as for improving the internal efficiency is the quality management. Several tools can be involved when dealing with this issue; one of these is the Statistical Process Control, which includes the employment of statistical methods and metrics to monitor and control a process' quality. In this paper, indeed, two statistical metrics are involved for assessing the process capability of a filler machine produced by an Italian company operating in the food context. Specifically, two processes are inspected: the slewing ring-pinion backlash and the handling clamps height check, both showing excellent performances after having carried out the control and provided appropriate adjustments. Results are also compared with those obtained from the Six Sigma theory, another tool involved for quality controls which is in line with principles of lean manufacturing. Moreover, for the second process, a software was implemented for speeding up operations and achieving benefits in terms of time. The reliability of these analysis is confirmed by the application of the ANOVA Gage R&R tool, which allowed to assess the precision of the measurement system involved.