180 likes | 320 Views
Optimizing and controlling process through statistical process control. Chapter 18 page 442 Doaa Abu Alwafa. STATISTICAL PROCESS CONTROL DEFINED. All process are affected by multiple factors such as: The environment the machines employed The materials used
E N D
Optimizing and controlling process through statistical process control Chapter 18 page 442 Doaa Abu Alwafa
STATISTICAL PROCESS CONTROL DEFINED • All process are affected by multiple factors such as: • The environment the machines employed • The materials used • The methods(work instruction) provides • The measurement taken • The manpower(people) who operate the process • These factors called the 5 M’s
STASTISTICAL PROCESS CONTROL DEFINED • Statistical process control (SPC) is a statistical method of separating variation resulting from special causes from variation resulting from natural causes in order to eliminate the special causes and to establish and maintain consistency in the process, enabling process improvement.
Rational for SPC • Control of variation • Continual improvement • Predictability of processes • Elimination of waste • Product inspection
Management’s role in SPC • Commitment • Training • Involvement See page 462
Role of the total quality tools • There are several tools: • Pareto charts • Cause and effect diagrams • Stratification • Check sheets • Histograms • Scatter diagrams • Run charts and control charts • Flow charts • Design of experiments • Five-s • Failure mode and effects analysis(FMEA)
Role of the total quality tools(continue) • With SPC, the total quality tools have a dual role: • First: they help eliminate special causes from the process so that the process can be brought under control. • Second: their second role comes into play when, from time to time, the control chart reveals cause or when the operators wants to improve a process that is in control.
Implementation and deployment of SPC • The implementation steps are divided into three phases: • preparation • planning • execution
Inhibitors of SPC • Capability in statistics • Misdirected responsibility for SPC • Failure to understand the target process • Failure to have processes under control • Inadequate training and discipline • Measurement repeatability and reproducibility • low production rates • See page 471-473