Yellow Belt - 06 - Basics - Metrics

Question 1

36. What are Defects Per Unit (DPU)?

Answer 1

1. DPU is an example of attribute data.
2. The total number of defects found during an inspection / Number of items(units) inspected.
3. A unit can be a car, engine, order form or smartphone.
4. DPU can be used to determine if a process is changing over time.

Question 2

37. How is DPU calculated?

Answer 2

DPU - # of defects (Total found during inpection) / # of units (total units inspected)

Question 3

38. What other measures can be recorded to see if a process changes over time.?

Answer 3

1. defects per opportunity (DPO)
2. defects per million opportunities (DPO)

Question 4

39. What are the two ways of working out Defects Per Opportunity (DPO)?

Answer 4

Two ways of working it out:

• (The total number of defects found during inspection ) / (Total number of Opportunities for defects to occur.)
• DPU/(Total number of Opportunities for defects to occur.)
• (Total number of Opportunities for defects to occur.) = Possible defect per unit * units inspected

Question 5

40. How is DPMO calculated

Answer 5

1. DPMO = DPO * (1000000 or 10⁶⁾

Question 6

41. What should the DPMO be?

Answer 6

1. DPMO = 6σ (3.4)

Question 7

42. What is Throughput Yield (TY)

Answer 7

1. Measures the ability of a process to produce units that are free of defects.
2. Use it when you need to mathematically measure the efficiency of a process.

Question 8

43. How is the Throughput Yield (TY) worked out?

Answer 8

1. Point estimate TY
   * Total # of defect-free units / total number of units
2. Long run average TY
   * TY = e^-du

Question 9

44. What is Rolled Throughput Yield (RTY)

Answer 9

1. Monitors the overall Yield of a series of processes
2. Product of the TY of each part of a process

Question 10

45. How do you calculate the Rolled Throughput Yield?

Answer 10

1. To calculate the RTY, first, calculate the TY for each part of the process. Then multiply the TY’s to calculate RTY

RTY = process 1 TY * process 2 TY * process 1 TY

Question 11

46. What is cycle time

Answer 11

1. The time it takes for a process to run from start to finish.
2. or the average time for a completed unit to come to the end of a process
3. it is the rate at which output is being produced.

Question 12

47. How is cycle time calculated?

Answer 12

1. Cycle time = (Production Time) / (quantity of units processed in the production time)
2. Order entry person processes 30 orders every hour. The cycle time is two mins per order.
3. 60 mins / 30 orders = 2 mins per order.
4. Cycle time should = Takt time.

Question 13

48. How do you reduce cycle time?

Answer 13

1. Continuous flow is also known as One-piece flow.
2. Reduce time spent installing equipment and changing equipment setups or settings.

Question 14

49. what is takt time?

Answer 14

1. Takt time sets the pace of production so that cycle times can be matched to customer demand.
2. It is the rate at which output needs to be completed to meet customer demand on time.
3. The cycle time should match the takt time if customer demand is to be met on time.

Question 15

50. How is Takt time calculated?

Answer 15

Takt time = Time to complete units / # of units to complete

A team of three order entry people are expected to process 120 orders per hour

takt time = (60 mins * 3) / 120 unit = 1.5 orders per min

Question 16

51. what is the cost of quality?

Answer 16

1. COQ provides tangible data which shows how quality affects the bottom line.
2. It describes the impact of poor quality.
3. It shows how resources prevents poor quality.
4. It shows how resources Appraise quality.
5. It shows how resources address internal and/or external failures
6. sometimes called “cost of poor quality” - COPQ

Question 17

52. what are the four types of COQ costs

Answer 17

1. Prevention costs
2. Appraisal costs
3. Internal failure costs
4. External failure costs

Question 18

53. what are the COQ Internal Failure costs?

Answer 18

1. These are costs used o remedy defects before the product or service is delivered to the
2. waste, scrap, rework, re-inspection, retesting, and failure analysis are all Internal Failure costs.

Question 19

54. what is the COQ prevention costs?

Answer 19

1. This is incurred to prevent or avoid quality problems.
2. Can include “quality planning”, “quality Specifications”, “Quality assurance”, “training”

Question 20

55. What are the COQ appraisal costs?

Answer 20

1. This comes from the measuring and monitoring activities related to quality.
2. Verification, testing, inspection, quality audits and supplier rating are all appraisal cost

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Question 21

56. what are the COQ External Failure costs?

Answer 21

1. These are costs incurred to remedy defects after the customer has received the product or service.

Question 22

57. how do you calculate COPQ

Answer 22

Prevention Costs + Appraisal cost + internal failure costs + external failure costs + hidden costs

Annual revenue