1. Manufacturing the Safe Product
Chapter 19

2. Generating Hazardous Characteristics
Improper production techniques
Failure to remove metal burrs, points or sharp edges
Removing too much wire insulation

3. Unauthorized Changes To reduce production costs, difficulties or both
Attempt to minimize work schedule interruption
Prevention requires control of changes

4. Evaluation of Changes
Change evaluated by design engineering department
Consider impact of possible change
Consider safety aspects with safety engineer

5. Controls on Changes Imposed / carried out for:
Manufacturer’s operations
Supplies
Components
Assemblies from vendors / subcontractors

6. Care of Safety-Critical Items
Require more care than non safety-critical
Determined from safety analyses
Always include:
Materials & components that are dangerous in themselves
Materials whose combinations are dangerous & must be separated
Safety devices

7. Safety-Critical Items
Tendency to minimize number of critical items
Too many critical items are ignored

8. Testing Inspection / testing of every item is prohibitive
Develop & follow test plan for greatest beneficial effect
Knowledge of criticality
Means to indicate if requirements are met
Indicates testing for maximum effectiveness

9. Manufacturing Defects
Production Deficiencies - Welding:
Poor welds degrade strength
Welding in contaminated conditions produce porous welds
Failure to clean welds leads to corrosion & loss of strength
Gaps producing short circuits

10. Manufacturing Defects
Production Deficiencies - Excessive Heat:
Degrade surface finishes to failure
Degrade metals
Heat can cause deformation or melting of plastics

11. Manufacturing Defects
Production Deficiencies - Assembly:
Critical parts separate in use
Stresses in assembly leading to failure under load

12. Manufacturing Defects
Production Deficiencies - Warning Labels:
Manufacturers vulnerable to claims of “failure to warn”
Obligation for replacement parts

13. Manufacturing Defects
Production Deficiencies - Components:
More failure due to weak connections between components
Connections may separate
Fittings may not be adequately tightened
Lack of cleanliness leads to clogging
Welds may fail
Hoses may be damaged or separate from couplings & whip

14. Production Errors Rush to meet production quotas or premium pay
Employee fatigue
Inadequate selection / training of workers
Lack of proper supervision

15. Production Errors Poor motivation / distraction
Unsatisfactory working conditions
Inadequate / poorly designed equipment, tools or facilities
Lack of instructions, drawings or specs

16. Quality Control Responsible for high quality output
Not responsible for production processes
Wouldn’t be necessary if faultless products were produced

17. Facts of Life
All mechanics will eventually make mistakes leading to poor workmanship
All inspectors will make mistakes & accept bad work
Some material will progress or be delivered with unknown / undetected defects

18. Quality Control Inspecting & testing
Manufacturer is responsible for product including parts from subcontractors
Responsible suppliers make own inspections & tests
Some manufacturers re-test suppliers’ critical items

19. Quality Control Records must be maintained
Identification of specific lots
Proof of passage of inspection
Inspections & tests done at times & locations where most effective
100% sampling for critical items

20. Quality Control
Inspections & tests reveal failure to reach prescribed limits
Inadequate or loose quality control leads to greater possibilities of failure

21. Quality Control Personnel
Parameters product must meet
Deficiencies possible
Criticality of items inspected
Recordkeeping reports

22. Definitions
Critical - fault likely to result in serious consequences (danger of loss of life or serious injury or certainty of major complain & damage to reputation)
Major / Serious - Probability of product failing to give good performance, likelihood of complaint

23. Definitions
Major / Less Serious - Some failure possible during use, likely to cause trouble for consumer, major defects in appearance or finish but no bearing on performance
Minor - slight defects in appearance & finish, technical faults unlikely to cause trouble or poor performance

24. Standardized Quality Control
Need detailed instructions on:
Means of verification
Frequency of sampling & levels of defectiveness
Records to be retained
Frequency of instrument calibration

25. Standardized Quality Control
Need detailed instructions on:
Action for out-of-control process
Procedure for design deviation
Means of identification for acceptable items
Marking of non-conforming items / segregation

26. Quality Control
All deficiencies brought to production personnel immediately
All deficiencies reported in writing to production manager
Report to design engineer if warranted

27. Deficiency Report Identify deficiency Where and when first encountered
Number of items / lots affected
Actions of quality control personnel to limit effects of problem

28. Advantages - Reduction in:
Costs of scrap / re-work
Ordering extra materials
Shipping costs on returns
Payment delays
Time for explaining problems to consumer

29. Advantages - Reduction in:
Consumer cost of removing / reinstalling replacement
Sales losses
Lost income
Damage caused

30. Manufacturing Checklist
Figure 19- 5
Page 252

31. Other Production Records
P.O.’s, advertising literature, test reports on suppliers’ items
Manufacturers’ reports on materials used in production
Lot numbers & quantities, components, serial numbers, dates of manufacture
Test reports of outside laboratories

32. Prototype Testing Last important phase
Reviewed by knowledgeable safety engineer