The term defect detection redundancy is used to indicate that several inspectors apply the same defect detection technique, which usually increases the defect overlap. Defect detection redundancy increases costs because inspectors are added but decreases the risk of undetected defects. Therefore some redundancy might be reasonable and advantageous.

Biffl, S., & Halling, M. (2003). Managing Software Inspection Knowledge for Decision Support of Inspection Planning. Managing Software Engineering Knowledge (pp. 231-249). Springer. [-]