How is the quality of products controlled through manufacture?

• Checking for accuracy and conformity to standards and tolerances
• Ensuring products are safe and reliable for end users
• Checks typically carried out after manufacturing is complete
• Can include visual inspections, automated camera checks or computer-guided analysis
• Testing methods may include destructive (breaking products to test limits) or non-destructive testing
• Comparison is made against a product specification sheet or industry standard
• Aims to ensure final product meets customer expectations and regulatory compliance

Advantages	Disadvantages
Less faulty products being sold to customers Helps maintain a good company reputation for quality Can highlight trends in faults for further investigation	Quality control can be expensive in labour and time May delay production line speed Waste is already created by the time fault is found Does not pinpoint where in the process the fault occurred

Applications: Casting parts, components in assembly lines, automotive engines, consumer electronics

Inspection:

Inspection involves measuring and checking that each product or a sample of products meet required tolerances and standards.

• 100% inspection – Every single unit is checked. Often used in critical components like aircraft parts.
• Normal sampling – A fixed sample (e.g. every 100^th item) is inspected. Balances cost and accuracy.
• Reduced inspection – Used when a supplier has consistently high quality. E.g. every 10,000^th item.

Computer-aided inspection:

Uses a Coordinate Measuring Machine (CMM) or laser scanning devices to digitally check complex shapes or surfaces with high precision. Useful for ensuring consistency in intricate parts like turbine blades or PCB boards.

Testing/checks:

Evaluates how well the product performs in use, under stress, and during its expected lifecycle.

• Test material strength or durability (destructive/non-destructive)
• Verify correct function under normal and extreme conditions
• Ensure all parts fit together precisely (fit & tolerance)
• Surface finish must be free from burrs or scratches
• Safety checks for sharp corners/edges, especially for consumer products
• Look for hidden defects in casting like air pockets or cracks
• Assembly checks to avoid missing screws or connections
• Thread integrity and smooth motion tested
• Review position and quality of branding elements or printed labels

Reducing cost of testing:

• Use statistical sampling rather than checking every item
• Go/no-go gauges to speed up basic dimension checks
• Limit destructive testing to random samples only
• Automate inspection to reduce labour costs

Non-destructive testing:

Tests the integrity of a part without damaging it. Ideal for expensive or critical components. Includes ultrasonic scanning, X-ray, dye penetrant, and magnetic particle testing to find cracks or voids.

Destructive testing:

Involves testing a product until it fails to understand its breaking point or durability. Common in safety-critical industries like aerospace, automotive, or construction materials.

Quality assurance (QA) is a proactive process applied throughout the production life cycle — from initial design to final delivery. It ensures that products are consistently high quality, defect-free, and fit for purpose.

• Incorporated into design, materials, production and delivery stages
• Prevents defects rather than detecting them after manufacture
• Focus on process improvement, not just product checking
• Often uses external certifications (ISO 9001, BSI Kitemark, CE mark)
• Ensures suppliers meet standards for parts and materials

Advantages	Disadvantages
Reduces the chance of errors reaching the customer Improves customer trust and satisfaction Lower waste and scrap costs due to early intervention Workers feel more valued and responsible for quality Leads to long-term improvements and process optimisation Promotes teamwork between departments	Training staff can be expensive and time-consuming Initial setup is slow and can meet internal resistance Requires management commitment and cultural change May be difficult to track all quality issues across stages

Applications: Medical devices, aerospace components, construction, electronics

Total quality management (TQM):

• TQM is a company-wide approach to embedding quality into everything an organisation does
• Involves all employees at every level, from management to production staff
• Encourages continuous improvement in products, services, and processes
• Reduces waste and increases productivity over time
• Often uses quality circles (small groups that meet to discuss improvements)

Advantages	Disadvantages
Reduces long-term costs by preventing faults Improves consistency of output Encourages teamwork and employee involvement Shorter production times due to fewer mistakes Better customer satisfaction and brand reputation	High investment in training and cultural change Slow to see benefits Can meet resistance from staff used to old systems Cost savings may take time to materialise

Applications: Manufacturing, logistics, IT services, healthcare

ISO 9000:

• A globally recognised series of standards for quality management systems
• Used by organisations to ensure consistency, legal compliance, and continual improvement
• Helps businesses document procedures and maintain accountability
• Improves customer satisfaction through reliable quality

Seven points they look at:

• Customer focus – understand and meet customer needs
• Leadership – strong vision and internal direction
• Engagement of people – ensure staff are empowered and involved
• Process approach – optimise workflows and resources
• Improvement – constantly aim to do better
• Evidence-based decision making – use data for planning
• Relationship management – strong collaboration with suppliers and customers

European Standards (EN):

• Developed by the European Committee for Standardization (CEN)
• Ensure compatibility and safety across European Union member states
• Harmonise technical specifications across different countries
• Facilitate trade and product conformity within the EU
• Cover areas such as product safety, manufacturing processes, and environmental impact
• Required for CE marking on many products sold in the European Economic Area

Key aspects they promote:

• Free movement of goods within the EU
• Technical consistency and mutual recognition
• Consumer protection and safety
• Environmental responsibility
• Innovation through standardised benchmarks

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British Standards (BSI):

• Published by the British Standards Institution (BSI)
• Set quality and safety benchmarks for products and services in the UK
• Voluntary, but often adopted as best practice or required in contracts
• Help ensure safety, reliability, and fitness for purpose
• Can apply across sectors – engineering, construction, education, etc.
• BS standards can be adopted into EN or ISO standards if aligned internationally

Principles they emphasise:

• Meeting legal and regulatory requirements
• Promoting quality assurance and consistency
• Improving customer satisfaction and trust
• Reducing risk and improving efficiency
• Supporting innovation and continual improvement

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