week 9: quality and maintenance management

Question 1

quality definitions

Answer 1

• transcendent (innate excellence)
• manufacturing based (free of errors)
• user based (measurable set of characteristics)
• product based (measurable set of characteristics)
• value based (cost and price)

Question 2

quality management plan ( product characteristics; variables vs attributes)

Answer 2

1. Define the characteristics of the product:
   a. Functionality
   b. Appearance
   c. Reliability
   d. Durability
   e. Recovery
2. Decide how to measure each characteristic
   a. Variables - easily quantifiable as real numbers
   b. Attributes - assessed by judgment
3. Set quality standards
   Acceptable level of quality needs to be defined
4. Control the quality against those standards
5. Find and correct causes of error
6. Continue to make improvements

Question 3

quality control: where should quality be controlled

Answer 3

• start of process (raw material)
• during (take place at any stage)
• after (ensure quality of end product)

Question 4

quality control: how should it be performed

Answer 4

• statistical process control (monitor process to see variation beyond normal variation)
• acceptance sampling ( batches of products inspected before or after process acceptance based on proportion of defectives to acceptable)

Question 5

quality control: errors in sampling

Answer 5

error 1:
- false positives where sample indicates traits that do not align with the whole population

error 2:
- false negative where sample does not indicate traits in popluation

Question 6

total quality management (TQM) objectives

Answer 6

• customer satisfaction
• improving continuously
• involving the entire workforce in quality management

Question 7

inspection technologies

Answer 7

• coordinate measurement machines
• scanning laser systems
• machine vision systems
• ultrasonic techniques

Question 8

maintenance types

Answer 8

• breakdown (equipment serviced or repaired only when it fails)
• preventative (equipment periodically inspected serviced, cleaned and replaced to prevent sudden failure)
• corrective or predictive (equipment and components are improved so reliable preventive maintenance carried out)