NCT Quality Control & Process Improvement 3 — Questions and Answers
Question 1: In fleet quality control, a 'comeback' rate measures:
- The percentage of vehicles returned for the same unresolved issue after repair (Correct answer)
- The rate at which older vehicles are cycled back into active service
- The frequency of technician re-training
- The number of warranty claims filed per quarter
Correct answer: The percentage of vehicles returned for the same unresolved issue after repair
Comeback rate tracks repeat repairs, directly reflecting technician quality and first-time fix effectiveness.
Question 2: Which quality control document provides a step-by-step procedure ensuring technicians perform maintenance tasks consistently?
- Fleet policy manual
- Standard Operating Procedure (SOP) (Correct answer)
- Work breakdown structure
- Corrective action report
Correct answer: Standard Operating Procedure (SOP)
Standard Operating Procedures define the exact steps for each task, reducing variability and ensuring consistent quality outcomes.
Question 3: When conducting a fleet maintenance audit, which element is MOST critical for evaluating quality system effectiveness?
- Number of vehicles in the fleet
- Evidence that nonconformances trigger corrective actions (Correct answer)
- Total maintenance budget spent
- Average technician tenure
Correct answer: Evidence that nonconformances trigger corrective actions
An effective quality system must demonstrate a closed-loop process where identified problems are tracked to resolution.
Question 4: A fleet organization implements a suggestion program where technicians submit process improvement ideas. This practice is BEST described as:
- Six Sigma DMAIC
- Kaizen (continuous improvement culture) (Correct answer)
- Benchmarking
- Statistical process control
Correct answer: Kaizen (continuous improvement culture)
Kaizen emphasizes small, continuous improvements driven by frontline employees who identify daily operational inefficiencies.
Question 5: Which of the following is an example of a leading quality indicator in fleet management?
- Number of roadside breakdowns last quarter
- Percentage of PM services completed on schedule (Correct answer)
- Total repair costs for the previous year
- Average vehicle downtime hours
Correct answer: Percentage of PM services completed on schedule
PM compliance rate is a leading indicator because it predicts future failures before they occur, unlike lagging indicators that record past events.
Question 6: In Six Sigma methodology, what does a process operating at '3 sigma' level produce approximately?
- 3.4 defects per million opportunities
- 66,807 defects per million opportunities (Correct answer)
- 308,537 defects per million opportunities
- 6,210 defects per million opportunities
Correct answer: 66,807 defects per million opportunities
A 3-sigma process yields approximately 66,807 defects per million opportunities; Six Sigma targets 3.4 DPMO.
Question 7: A fishbone (Ishikawa) diagram in fleet maintenance quality analysis organizes potential causes into categories. Which set represents the standard 'bones'?
- Plan, Do, Check, Act
- Man, Machine, Method, Material, Measurement, Environment (Correct answer)
- Define, Measure, Analyze, Improve, Control
- Input, Process, Output, Feedback
Correct answer: Man, Machine, Method, Material, Measurement, Environment
The classic Ishikawa fishbone uses the 6M categories to systematically explore all potential contributors to a defect.
NCT Quality Control & Process Improvement 3
In fleet quality control, a 'comeback' rate measures: