CONTROL CHARTS  CHARTS USED FOR PROCESS CONTROL.STATISTICAL DEVICE USED FOR CONTROL OF REPETITIVE PROCESSES.  DEVELOPED BY DR.W A SHEWART.  VARIABILITY EXISTS IN ALL REPETITIVE PROCESSES ---- DUE TO CHANCE CAUSE ---- DUE TO ASSIGNABLE CAUSE  VARIATION IN ANY MANUFACTURED PRODUCT IS INEVITABLE

CHANCE CAUSE INEVITABLE DIFFICULT TO TRACE DUE TO INHERENT CHARACTERISTIC OF PROCESS OR MACHINE

ASSIGNABLE CAUSE CAN BE TRACED AND DETECTED DUE TO— DIFFERENCE IN MACHINES DIFFERENCE IN MATERIALS DIFFERENCE IN WORKERS DIFFRENCE IN THEIR RELATIONSHIPS

STATISTICAL QUALITY CONTROL EMPLOYED TO CONTROL,IMPROVE AND MAINTAIN QUALITY. ACTIVITIES: SYS COLLECTION AND GRAPHIC REP OF DATA ANALYZING DATA MANAGEMENT ACTION

BENEFITS EFFICIENCY REDUCTION OF SCRAP EARLY DETECTION OF FAULT QUALITY IMPRAVEMENT ADHERENCE TO SPECIFICATION

CONTROL CHARTS X BAR AND R CHARTS (MEASUREMENT OF QUALITY CHARACTERISTIC) P CHART(CHART FOR FRACTION DEFECTIVE) C CHART (CHART FOR NO. OF DEFECTS/UNIT)

CONSTRUCTION OF CHART CHOICE OF VARIABLE(LIKELY TO REDUCE COST) BASIS OF SUB GROUP SIZE OF SUBGROUP FREQUENCY OF SAMPLING CONTROL LIMITS