Testing as a Part of Quality Management

Reasons for Testing

1. Manufacturing defects are inevitable:

Despite a high level of automation, production processes are still prone to errors. Typical defects include:

• cold joints, short circuits, broken traces,
• missing or incorrectly placed components,
• defective or counterfeit parts.

2. Cost reduction through early detection:

The economics of testing is based on the principle “the sooner you catch a fault, the cheaper it is to fix.” Detecting defects immediately after assembly (inline) is significantly more cost-effective than later repairs in the service chain.
 

3. Ensuring compliance with standards and specifications:

In industries such as automotive, aerospace, healthcare, and defense, verifying the functionality and safety of components is a legal requirement.

Types of Testing

AOI (Automated Optical Inspection):

Automated visual inspection checks the placement and orientation of components, solder quality, and the presence of mechanical defects.

ICT (In-Circuit Test):

Used to test individual nodes in the circuit – for example, by measuring resistances, capacitances, voltage drops across PN junctions, etc. It uses dedicated test points and is fast and reliable.

FCT (Functional Test):

Verifies the behavior of the entire device under real or simulated operating conditions. It checks firmware functionality, I/O logic, and response to specific signals.

Challenges and Trends in Testing
 

• Miniaturization and complexity of circuits: leads to limited access to test points.
• Pinless testing (Boundary Scan, JTAG): enables internal functions of chips to be tested without physical access to all pins.
• Integration with MES and Industry 4.0: modern test stations communicate in real time with production systems, collecting and analyzing data for feedback and process improvement.

Conclusion: Testing as an Investment in Reliability

From the perspective of production engineering, testing is not just a cost, but an investment in quality. A well-designed testing process enables faster production, reduced scrap rates, and higher customer satisfaction.

Note: Testing does not replace proper design – but it helps identify errors that inevitably occur during design or manufacturing.