Industrial Engineering and Operations Research

A: Governing principle: Little’s Law holds for effective WIP and effective throughput in steady state. Applied here: rework increases effective WIP to 340 × 1.25 = 425 items while net throughput stays 18/day, giving CT ≈ 23.6 days, but only if rework consumes capacity; the question frames extra touches without added close-out, so effective WIP seen by the system is 340 while flow time stretches by 1.25 → 18.9 days. Distractor D traps engineers who inflate WIP and forget the stated assumption about net close-out capacity.

A: Governing principle: alarms protect against awareness gaps, not against flow paths that bypass control elements. Applied here: LSHH alerts on level but cannot limit instantaneous flow through an unrestricted bypass, so downstream slugging remains credible. Distractor A catches people who equate level alarms with carryover prevention, ignoring response time and flow area.

A: Governing principle: corrosion mechanism follows the controlling species and operating envelope. Applied here: CO2 partial pressure and temperature favor sweet corrosion; H2S is below thresholds for SSC, and MIC or O2 pitting are secondary without evidence. Distractor C appeals to engineers with water-treatment backgrounds who over-weight shutdown conditions.

A: Governing principle: PSV sizing governs mass flux during the governing contingency, independent of set pressure. Applied here: a smaller actual valve than shown reduces relieving capacity even if set pressure and MAWP remain correct. Distractor D attracts engineers focused on mechanical loads rather than flow capacity.