Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If you continue browsing the site, you agree to the use of cookies on this website. See our User Agreement and Privacy Policy.

Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If you continue browsing the site, you agree to the use of cookies on this website. See our Privacy Policy and User Agreement for details.

Like this presentation? Why not share!

- Staphylococcus & streptococcus by Mohammad Ihmeidan 905 views
- Block 33 HMA Overlays c SP 13 by Chris Yarnell 949 views
- Block 14 Superpave Mix Design 13 by Chris Yarnell 3809 views
- Superpavemixdesign by pradip dangar 657 views
- enterobacteracae by nechir-zakho 3596 views
- Block 4 SP 14 by Chris Yarnell 2746 views

No Downloads

Total views

658

On SlideShare

0

From Embeds

0

Number of Embeds

1

Shares

0

Downloads

42

Comments

0

Likes

1

No embeds

No notes for slide

- 1. Senior/Graduate HMA Course Quality control/quality assurance Control ChartsConstruction QC/QA Control Charts 1
- 2. Control ChartsConstruction QC/QA Control Charts 2
- 3. Variation - Chance Causes - Assignable CausesConstruction QC/QA Control Charts 3
- 4. Chance Causes1. Everything varies2. Individuals are unpredictable3. Groups from a constant system tend to be predictable Construction QC/QA Control Charts 4 8-31
- 5. Example: Chance Causes1. People live to different ages2. No one knows how long he or she will live3. Insurance companies can predict the percentage of people who will live to certain ages Construction QC/QA Control Charts 5
- 6. Assignable CausesIf identified - It can be eliminatedConstruction QC/QA Control Charts 6
- 7. Benefits of Control Charts- Early Detection of Trouble- Decrease Variability- Establish Process Capability- Reduce Price AdjustmentCosts- Decrease InspectionFrequencyConstruction QC/QA Control Charts 7
- 8. Benefits of Control Charts• Basis for Altering Specification Limits• Permanent Record of Quality• Provide a Basis for Acceptance• Instill Quality AwarenessConstruction QC/QA Control Charts 8
- 9. Control Chart Analysis AASHTO “To Develop a Quality Control/Quality Assurance Plan for Hot Mix Asphalt”Construction QC/QA Control Charts 9
- 10. Upper control limit Lower control limit 1 2 3 4 5 6 7 Lot NumberConstruction QC/QA Control Charts 10
- 11. Statistical Control Chart Upper Control Limit Data Points Target Value Lower Control LimitConstruction QC/QA Control Charts 11
- 12. Five lines on a statistical process control chart • Target value • Warning upper control limit • Warning lower control limit • Action upper control limit • Action lower control limitConstruction QC/QA Control Charts 12
- 13. Upper Control Limit Mean Lower Control Limit 1 2 3 4 5 6 7 Lot NumberConstruction QC/QA Control Charts 13
- 14. Statistical Control Charts Upper and Lower Warning Control Limits UWCL = X + { 2 (s) / (n)1/2 } LWCL = X + { 2 (s) / (n)1/2 }Construction QC/QA Control Charts 14
- 15. Statistical Control Charts Upper and Lower Action Control Limits UWCL = X + { 3 (s) / (n)1/2 } LWCL = X + { 3 (s) / (n)1/2 }Construction QC/QA Control Charts 15
- 16. Example Problem• Given: – Target asphalt binder content: 5.7 % – Standard deviation – 0.25 % – The rolling average is based on five data pointsConstruction QC/QA Control Charts 16
- 17. Example Problem warning limits UWCL = X + { 2 (s) / (n)1/2 } UWCL = 5.7 + { 2 (.25) / (5)1/2 } UWCL = 5.9Construction QC/QA Control Charts 17
- 18. Example Problem warning limits LWCL = X - { 2 (s) / (n)1/2 } LWCL = 5.7 - { 2 (.25) / (5)1/2 } LWCL = 5.5Construction QC/QA Control Charts 18
- 19. Example Problem warning limits UACL = X + { 3(s) / (n)1/2 } UACL = 5.7 + { 3 (.25) / (5)1/2 } UACL = 6.0Construction QC/QA Control Charts 19
- 20. Example Problem warning limits LACL = X - { 3 (s) / (n)1/2 } LACL = 5.7 - { 3 (.25) / (5)1/2 } UWAL = 5.4Construction QC/QA Control Charts 20
- 21. Look for Assignable Cause If:• One point is outside of control limits• Eight consecutive points are on one side ofthe target value Construction QC/QA Control Charts 21
- 22. Interpreting X & R Charts
- 23. Chart 6 Action Limit (UCL) 5 Warning Limit% Air Voids 4 3 Action Limit (LCL) 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 24. Range (R) Chart 8 (UCL) 7 6% Air Voids 5 4 3 2 1 (LCL) 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 25. Control Charts Rules of Thumb Lack of Control Occurs When: Change in X, R Constant Change in R, X Constant Change in Both X & R
- 26. Sustained Shift in 6 Action Limit Mean Incr eases 5 War ning Li mi t% Air Voids 4 3 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 27. Trend in 6 Action Limit 5 Warning Limit% Air Voids 4 3 Production "Upward Drift" 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 28. Irregular Shift in 6 Action Limit (UCL) 5 Warning Limit% Air Voids 4 3 Action Limit (LCL) 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 29. Sudden Change in R 9 8 (UCL) 7% Air Voids 6 5 4 3 2 1 (LCL) 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 30. Gradual Change in R 9 8 (UCL) 7 6% Air Voids 5 4 3 2 1 (LCL) 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 31. Irregular Shift in & R 6 Action Limit (UCL) 5 Warning Limit% Air Voids 4 3 Action Limit (LCL) 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 32. Lack of Control? 6 Single Point Above Action Limit Action Limit 5 Warning Limit% Air Voids 4 3 Eight Points Below Target 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Sample Number
- 33. Questions?Construction QC/QA Control Charts 33

No public clipboards found for this slide

×
### Save the most important slides with Clipping

Clipping is a handy way to collect and organize the most important slides from a presentation. You can keep your great finds in clipboards organized around topics.

Be the first to comment