Comprehensive and Detailed Explanation:

In-process checks observe service performance while it is taking place, enabling staff to correct a problem before more customers are affected. Machine diagnostics can detect developing faults in refrigeration, heating, elevators or hotel systems immediately. Departure interviews and telephone surveys provide useful feedback but are commonly conducted after the experience or require additional processing. The fastest techniques in this scenario therefore provide direct, contemporaneous information. Management should also investigate root causes, not simply restore service without learning. Where consequences are significant, managers should prioritise preventive controls, reliable monitoring and prompt restoration. Performance measures such as downtime, MTBF, repair time and availability help identify weaknesses. The chosen technique must also account for costs, safety and the possibility of common-cause failures. The required selections are in-process checks and machine diagnostic checks. These choices address the particular category named in the question, whereas the remaining alternatives describe other activities, dimensions or outcomes. Documented responsibilities, suitable spare capacity and tested recovery arrangements can reduce the duration and consequences of disruption.

Study Guide Reference: CIPS L5M9 – Explain techniques in failure prevention and recovery that can be applied in operations management; the uploaded question bank cites study-guide page(s) 96.