Chapter 9 Learning Ryan Dresher MGMT 580 Attributes

Chapter 9 Learning Ryan Dresher MGMT 580

Attributes n n n Characteristics describing product or service (Summers, 2010) Used because the product or service is immeasurable Advantages n n n Easy Inexpensive Measures level of quality Show stability of process over time Disadvantages n n Tracks only quantity of non-conformances No indication of weight of non-conformance No indication of why the product or process changed Specific criteria must be established for data collection (Summers, 2010)

Fraction Non. Conforming Chart p Chart n n A type of attribute chart for tracking nonconforming units over time Shows when products are n n n Good or bad Correct or incorrect Working or not working (Summers, 2010) Centerline, Upper and Lower Control Limits are defined Interpretation n Points should randomly cross back and forth across CL Points should trend toward LCL showing improvement in processes Should not be any sudden shifts in data (Summers, 2010)

Number of Non. Conformities c Chart n n An attribute chart for tracking the count of nonconformances within product or service Ex. n n n n Number of defects in per ship built Number of defects per aircraft Number of bubbles in a piece of glass More than one type of non-conformance can be counted A constant sample size must be used UCL = c+3√c LCL = c+3√c Interpretation n n Should be no sudden shifts in data Should have points trending toward zero showing process improvement (Summers, 2010)

C Chart

References n Summers, D. C. S. (2010). Quality. (5 ed. ). Pearson College Div.