TS Continuous Improvement Techniques 2 — Questions and Answers
Question 1: Which Lean metric measures the ratio of value-added time to total lead time in a process?
- Process cycle efficiency (Correct answer)
- Takt time ratio
- Defect escape rate
- First pass yield
Correct answer: Process cycle efficiency
Process cycle efficiency (PCE) is calculated as value-added time divided by total lead time, revealing how much of the process actually adds value.
Question 2: A test team notices recurring defects in integration testing. Which continuous improvement tool would best map the sequence of causes leading to this problem?
- Control chart
- Scatter diagram
- Fishbone (Ishikawa) diagram (Correct answer)
- Pareto chart
Correct answer: Fishbone (Ishikawa) diagram
A fishbone (Ishikawa) diagram systematically maps cause-and-effect relationships, making it ideal for tracing sequential causes of recurring defects.
Question 3: In a Kaizen event, what is the primary timeframe typically targeted for completing improvements?
- One to two weeks
- One to five days (Correct answer)
- One to three months
- A single eight-hour shift
Correct answer: One to five days
Kaizen events (or blitzes) are focused, rapid improvement activities typically completed within one to five days.
Question 4: Which statistical process control signal indicates a process shift when seven consecutive points appear on the same side of the centerline?
- Rule of seven (Correct answer)
- Three-sigma rule
- Bimodal pattern
- Stratification signal
Correct answer: Rule of seven
The 'rule of seven' (Nelson rule) flags a non-random process shift when seven or more consecutive points fall on one side of the mean.
Question 5: A software test team wants to reduce the time between code commit and test execution. Which DevOps/CI metric directly measures this lag?
- Mean time to restore
- Lead time for changes (Correct answer)
- Change failure rate
- Deployment frequency
Correct answer: Lead time for changes
Lead time for changes measures the duration from code commit to production-ready delivery, reflecting pipeline efficiency.
Question 6: During a retrospective, a team agrees that test case reviews are taking too long. Using PDCA, which phase involves trialing a shorter review checklist on one sprint?
- Plan
- Do (Correct answer)
- Check
- Act
Correct answer: Do
The 'Do' phase of PDCA is where the team executes a small-scale experiment or pilot, such as trialing a new checklist on one sprint.
Question 7: Which Lean concept specifically targets reducing unnecessary motion and transportation of work items in a test workflow?
- Mura elimination
- Muda elimination (Correct answer)
- Muri elimination
- Poka-yoke
Correct answer: Muda elimination
Muda refers to waste in Lean, and unnecessary motion and transportation are two of the eight classic categories of muda to eliminate.
TS Continuous Improvement Techniques 2
Which Lean metric measures the ratio of value-added time to total lead time in a process?