Basic Quality Control Tools

Flowchart Check sheet Cause-effect diagram Pareto chart Histogram Scatter diagrams Control chart

Flow Chart Shows each of the steps required to produce a product or provide a service. –Actions depicted as rectangles –Waits or inventories are inverted triangles –Decision points as diamonds –Arrows show direction of flow –Circles as start, stop or transition Used for creating visualization of a process Have you identified the critical processes for your operations?

Flow Chart Example You can see from a flow diagram who depends on you and whom you can depend on. You can now take joy in your work.

Check Sheet             8        4     Shifts Defect Type        Total Defects 5 3 Records the frequency of occurrence of problems and/or errors Quality in all aspects of life “I keep data on my physical fitness. The data does help me make decisions on whether I’m ready, to compete in different events.”

Check Sheet COMPONENTS REPLACED BY LAB TIME PERIOD: 22 Feb to 27 Feb 2005 REPAIR TECHNICIAN: Bob TV SET MODEL 1013 Integrated Circuits |||| Capacitors |||| |||| |||| |||| |||| || Resistors || Transformers |||| Commands CRT |

Pareto Chart Causes of poor quality Percent from each cause Machine calibrations Defective parts Wrong dimensions Poor Design Operator errors Defective materials Surface abrasions (64) (13) (10) (6) (3) (2) Indicates which problem needs the most attention.

Fishbone Diagram Quality Problem MachinesMeasurementHuman ProcessEnvironmentMaterials Faulty testing equipment Incorrect specifications Improper methods Poor supervision Lack of concentration Inadequate training Out of adjustment Tooling problems Old / worn Defective from vendor Not to specifications Material- handling problems Deficiencies in product design Ineffective quality management Poor process design Inaccurate temperature control Dust and Dirt Powerful visual tool to categorize possible ideas of why failure occurred

Histogram Indicates the distribution of deviations from a standard bell- shaped curve

Histogram “From % To %”

Scatter Diagram Used for finding correlations among variables. Variable ‘x’ Variable ‘y’

Control Chart Used to determine if a process is in control.

Control chart Time System Average Prior System Average Control limit Special Cause Variation Quality Assurance to Prevent New System Average Quality Improvement to Achieve Quality Quality Improved Change to Process Level or Frequency of Measure

Conclusion Control Chart Flow Chart Histogram Check Sheet Pareto Chart Scatter plot Ishikawa Diagram