Where did total quality control come from?
Armand Feigenbaum, an American quality engineer at General Electric, argued in the 1950s that inspecting finished work was too late and too narrow. Quality is decided by marketing, design, purchasing, production and service together, so it has to be managed as one system. Japanese manufacturers adopted the idea in the 1960s as company-wide quality control, and it grew into what is now called total quality management (TQM).
How is total quality control different from quality control?
| Quality control (QC) | Total quality control (TQC) | |
|---|---|---|
| Scope | Inspection and testing of the product | Every function that affects the product |
| Owner | Quality or inspection team | Every department and every person |
| Timing | Mostly after the work is made | From design through to after-sales service |
| Aim | Find defects | Prevent defects and reduce the cost of quality |
TQC is also narrower than TQM. TQC centres on controlling quality across the business; TQM adds customer focus, leadership and continual improvement as a full management philosophy.
What are the four types of quality cost?
Feigenbaum divided the cost of quality into four groups, and the idea is to spend more on the first two so the last two fall:
- Prevention cost. Training, planning, process design and error-proofing.
- Appraisal cost. Inspection, testing and audits.
- Internal failure cost. Scrap and rework found before shipment.
- External failure cost. Returns, warranty claims and lost customers.
How do you apply total quality control?
- Set quality requirements with the customer and write them into specifications.
- Build checks into each function, not only at final inspection.
- Train operators to check their own work and stop when something is wrong.
- Use data, such as defect rates and first pass yield, to see where quality is slipping.
- Fix root causes with structured problem solving, then confirm the fix held.