i think you should read from "Essentials of Electronic Testing for Digital, Memory and Mixed-Signal VLSI Circuits (Frontiers in Electronic Testing--agrawal and bushnell)" book. page nos. 71 onwards.
Hi,
To understand Fault collapsing and fault equivalence, go through the following two books:
1. Essentials of Electronic Testing for Digital, Memory and Mixed-Signal VLSI Circuits (Frontiers in Electronic Testing--agrawal and bushnell)" book.(See sandeep_sggs reply)
2. VLSI Test Principles and Architecture. (pdf available online)