Introduction to Test Effectiveness

The objective of a test in manufacturing is to ensure that there are no defects on boards being produced. This means that the correct components are fitted, they work properly and have the correct orientation in the  position where they are required to be. Electrical connectivity must be correct without opens / shorts with reliable solder connections. 

The PCOLA - SOQ method estimates the manufacturing test effectiveness of the solution provided at the beginning of the project. 

It allows both component and pin coverage to be defined for a printed circuit board.

Component Coverage PCOLA

Presence
Correctness
Orientation
Live
Alignment

PIN Coverage SOQ

Shorts
Opens
Quality

It is a comprehensive and thorough method of analysing effectiveness of a manufacturing test. It allows test strategies to be developed that can include additional test techniques to maximise overall effective test coverage.

Design for Testability (DfT) methods ensure that board designers think about test coverage and test effectiveness already in the design phase.
There are also software tools available on the market that support the process of analyzing and documenting the test design.