For predicting (i) the defect contents of any software development phase output (with particular emphasis on the software requirements analysis phase); and (ii) the defects finding effectiveness of corresponding SQA review activities applicable to that phase (here SRS reviews); Michael Kläs, et al. [17] propose a hybrid model-based solution, combining the opinions of experts and the history of past projects undertaken in the organization. This is carried out in order to quantitatively aid management in (i) both planning and executing SQA activities for new software development projects; (ii) ensuring the mitigation of software quality related risk in the finished product; and (iii) ascertaining whether the planned level of risk reduction has been realised. The authors also discuss a case study related to the Independent Verification and Validation activity of one mission-critical, onboard space system software product at the Japanese Aerospace Agency JAXA. Among the possible causal factors (about 100, as per Jacobs J., et al. [21]) affecting defect injection and defect detection, a specific list of factors applicable to the current context is identified. Opinions of experts are then obtained
on the influence of those factors through a questionnaire. The defects present are then estimated by multiplying,