OM-Week_4b

QUALITY TOOLS

Check Sheets

  • Purpose: Collect data effectively.

    • Recording defects by type.

    • Logging locations of defects.

    • Counting safety incidents.

  • Example: Production operator tracks defects using check sheets to identify frequently occurring types.

  • Usage:

    • Manual: Pen and paper for low data volume.

    • Microsoft Excel: For higher data volumes or automated data collection.

Pareto Diagram

  • Origin: Developed by Vilfredo Pareto, noting that 80% of effects come from 20% of causes.

  • Application: In quality management, useful for identifying key defects that require attention.

  • Chart Features:

    • Bars represent frequency or cost, arranged from longest to shortest.

    • Used for problem analysis, process improvement, and root cause analysis.

  • Creation Methods:

    • Manual or software (Excel, Minitab, Python).

Control Charts (Time Plot)

  • Purpose: Monitor process variation over time, developed by Dr. Walter A. Shewhart.

  • Components:

    • Control line: Ideal standard visualization.

    • Upper/Lower control limits: Acceptable variations.

  • Interpretation: Points outside control limits indicate process issues.

  • Tools: Excel, Minitab.

Histogram

  • Introduction: Introduced by Karl Pearson; a frequency plot identifying anomalies.

  • Usage: Recognizing data range spikes indicating significant events.

Scatter Diagram

  • Description: Plots pairs of numerical data to identify correlations.

  • Applications: Compare variables (e.g., customer satisfaction vs. response time).

  • Correlation Types:

    • Positive: Strong relationship between variables.

    • No correlation: Points appear random.

  • Example: Analyzing technician education versus complaint rates shows a negative correlation.

Cause and Effect Diagram

  • Overview: Graphical representation of relationships between causes and effects.

  • Also known as: Fishbone or Ishikawa diagram, developed by Kaoru Ishikawa.

  • Purpose: Identify root causes for process improvements and reducing defects.

  • Categories: Methods, Machines, People, Materials, Measurement, Environment.

TQM Benefits

  • Enhanced market image.

  • Higher productivity and profitability.

  • Customer focus and satisfaction improvement.

  • Reduced defects and waste.

  • Increased employee morale and job security.