Control charts

manoeuvre Charts Control Charts are use to distinguishes between specializes or common-cause of vicissitude that Is present In a process. There are two basal types of control charts- Variables Quantitative data (Measured) places Qualitative data (Counted) Variable Control Charts Use actual measurements for charting Types- bonnie & Range charts Median & Range charts Average & Standard deviance charts Individual & Moving Range charts Run Charts Attribute Control Charts use pass/fall or go/no-go Judgment Type improvement.To determine the process capability. For decisions In regard to reaping specifications. For current decisions in regard to recently produced items. Average & Range charts (0 and R) Guidelines for subgroup sizes (n)- As n increases the CLC become closer to central line. 2. As n increases the recapitulation cost per subgroup increases. 3. Distributions for averages of subgroups are nearly normal for n = 4 4. If n = 10 use the s -chart instead of R-chart . N = 5 un remarkably being used in industry 6.The percentage of product that fall within any pair of values may be predicted with the highest arcdegree of assurance. It permits the consumer to use the producers data The operator is performing satisfactorily from a feeling viewpoint. PROCESS IN CONTROL (Natural pattern of variation) About 34% of the plan points in an imaginary band between one standard deviation on both sides of the central line About 13. 5% of the plan points in an imaginary band About 2. 5% of the plotted points in an imaginary band