OM Process Optimization 2 — Questions and Answers
Question 1: Which Lean concept focuses on producing only what is needed, when it is needed, and in the amount needed?
- Just-in-Time (JIT) (Correct answer)
- Kanban pull system
- Takt time balancing
- Single-piece flow
Correct answer: Just-in-Time (JIT)
Just-in-Time (JIT) is the Lean philosophy of producing exactly what is needed at the right time in the right quantity to eliminate overproduction waste.
Question 2: A process has a cycle time of 45 seconds and customer demand requires one unit every 60 seconds. What does this indicate?
- The process has excess capacity (Correct answer)
- The process is a bottleneck
- Takt time equals cycle time
- The process needs more resources
Correct answer: The process has excess capacity
When cycle time (45s) is less than takt time (60s), the process has excess capacity and is not the constraint.
Question 3: In Six Sigma, what does the term 'sigma level' primarily measure?
- Process speed relative to competitors
- The number of defects per million opportunities (Correct answer)
- Employee productivity rates
- Cost of quality as a percentage of revenue
Correct answer: The number of defects per million opportunities
Sigma level quantifies process capability by measuring defects per million opportunities (DPMO), with 6 sigma equaling 3.4 DPMO.
Question 4: Which tool is best suited for identifying the root causes of a problem by categorizing potential causes into major categories?
- Pareto chart
- Control chart
- Ishikawa (fishbone) diagram (Correct answer)
- Scatter diagram
Correct answer: Ishikawa (fishbone) diagram
The Ishikawa or fishbone diagram organizes potential root causes into categories (e.g., Man, Machine, Method, Material) to visually trace a problem to its source.
Question 5: What is the primary purpose of a SIPOC diagram in process improvement?
- To map detailed process steps with timing
- To provide a high-level overview of a process and its boundaries (Correct answer)
- To identify statistical variation in outputs
- To rank defects by frequency
Correct answer: To provide a high-level overview of a process and its boundaries
SIPOC (Suppliers, Inputs, Process, Outputs, Customers) gives a macro-level view of a process and defines its scope before detailed analysis begins.
Question 6: During a process audit, you find that workers frequently deviate from the standard operating procedure. What is the BEST first step?
- Retrain all workers immediately
- Investigate why the deviation occurs before enforcing compliance (Correct answer)
- Update the SOP to reflect current practice
- Implement stricter supervision
Correct answer: Investigate why the deviation occurs before enforcing compliance
Understanding why deviations occur may reveal that the SOP is outdated, impractical, or that workers have found a better method before enforcing or rewriting it.
Question 7: Which statistical method is used to determine whether two variables have a linear relationship in process optimization?
- Chi-square test
- Regression analysis (Correct answer)
- ANOVA
- Hypothesis testing
Correct answer: Regression analysis
Regression analysis quantifies the relationship between a dependent variable and one or more independent variables to predict process outcomes.
OM Process Optimization 2
Which Lean concept focuses on producing only what is needed, when it is needed, and in the amount needed?