Which software process model combines rapid prototyping with the controlled systematic aspects of the Waterfall model?
Option A is correct. The RAD model (proposed by James Martin) emphasizes user involvement, automated GUI building tools, and rapid prototyping structured into short 60-90 day cycles.
What term describes refactoring existing software code to improve its internal non-functional structure without changing its external observable behavior?
Option B is correct. Code Refactoring is the disciplined process of restructuring existing computer code—changing the factoring—without altering its external behavior.
Which requirement validation technique involves a formal step-by-step examination of SRS documentation by a peer review team to detect defects?
Option C is correct. Inspection (Fagan Inspection) is a formal peer review technique where trained reviewers systematically inspect requirements documents for defects, ambiguities, and inconsistencies.
In software maintenance, what percentage of total lifetime software maintenance cost is typically attributed to Perfective Maintenance?
Option A is correct. Empirical studies by Lientz and Swanson show that Perfective Maintenance (adding new user features and enhancements) accounts for over 50% of total software maintenance effort.
Which software process model introduced by Harlan Mills emphasizes mathematical verification of correctness to produce zero-defect software?
Option C is correct. Cleanroom Software Engineering uses formal mathematical specifications, statistical quality control, and rigorous correctness proofs to prevent defects before coding.