Quality control and inspection in manufacturing

Quality Control in Manufacturing

Quality Control refers to all the measures a company puts in place to ensure its products and services meet desired specifications and client expectations.

A key part of quality control is setting up and following manufacturing processes that ensure consistency and quality.
It also involves using inspection techniques to check the output for defects.
Different industries have various standards they adhere to, such as ISO 9001 in manufacturing.

Statistical Process Control (SPC)

SPC is a method of quality control that involves using statistical methods to monitor and control a process.
It helps ensure the process operates at its full potential to produce conforming product.
It’s about preventive maintenance rather than finding and discarding defective items after they’ve been produced.

Corrective Actions

If a product does not meet the desired specifications, corrective actions are taken.
Possible actions could be to recalibrate machines, retrain employees, or review the manufacturing process to find potential improvements.

Inspection in Manufacturing

Inspection refers to an organised examination or formal evaluation exercise in manufacturing.

In manufacturing, the goals of inspection are to control quality, prevent, identify and eliminate potential defects and malfunctions.
Manual inspection could involve visual checks, whereas automated inspection might use CMM (Coordinate Measuring Machines).

First Article Inspection (FAI)

The first article inspection is a planned, comprehensive, and documented inspection and verification process.
The objective is to verify the production method and demonstrate that the manufacturing process has produced an item that complies with all product requirements.

In-Process Inspection

In-process inspections aim to prevent defects and help managers identify and resolve quality problems.
Carried out during the manufacturing process, rather than after production has been completed.

Final Inspection

A final inspection serves as the last opportunity to capture and correct any defects or non-conformances prior to a product’s release.
It also serves to ensure that the product has been produced to the required specifications and quantities.

Online and Offline Inspection

Online inspection is when products are inspected during the manufacturing process.
Offline inspection is done after the product has been manufactured.
Online inspection is real-time and preferable as it allows for immediate feedback into the manufacturing process.

Tools and Equipment for Inspection

Common tools and equipments for inspection include visual inspection aids, hand tools such as callipers and micrometers, and examination tools like CMMs, spectrometers, and hardness testers.

Non-Destructive Testing (NDT)

Non-destructive testing is a way to inspect the integrity of a product or system without impairing its usefulness.
Common techniques include ultrasonic, magnetic (including Magnetic Particle Inspection), dye penetrant inspection, radiographic, and eddy-current testing.

Safety in Inspection

Inspection activities should be carried out safely, using protective clothing where necessary and following relevant safety procedures.
Adequate light and inspection work areas safe from environmental impacts (cold, rain, heat) should be provided.
Handling tools and equipment should be done carefully to avoid accidents and product damages.

Waste and Sustainability

Proper handling and disposal of waste from inspection activities such as defective parts and inspection aids are important.
Emphasis should be given to recycling and reusing where feasible, to promote sustainability.