ABSTRACT
Chapter 13 examines the links between statistical process control and the quality management system, including procedures for out-of-control processes. It looks at the role of teamwork in process control and improvement and explores the detail of the never-ending improvement cycle. It also examines Taguchi methods for cost reduction and quality improvement.
The main objective of the system is to cause improvements through reduction in variation in processes. The system should apply to and interact with all activities of the organization. The role of the management system is to define and control processes and methods. The system audit and review will ensure the processes are followed or changed.
Teamwork plays a vital role in continuous improvement. In most organizations it means moving from ‘independence’ to ‘interdependence’. Inputs from all relevant processes are required to make changes to complex systems. Good communication mechanisms are essential for successful SPC teamwork and meetings must be managed.
Control charts should not only be used for control but as an aid to reducing variability. The progressive identification and elimination of causes of variation may be charted and the limits adjusted accordingly to reflect the improvements.
Never-ending improvement takes place in the Deming cycle of plan, implement (do), record data (check), analyse (act) (PDCA). The Japanese engineer Taguchi has defined a number of methods to reduce costs and improve quality. His methods appear under four headings: the total loss function; design of products processes and production (APQP/ASQP); reduction in variation; and statistically planned experiments. Note is also made of the role of ‘big data’ analytics.
