1. Intelligent Maintenance Program
Hiromi Inokuchi
National Institute of Radiology Sciences, Japan

2. Objective
☑ About the aircraft maintenance
How did they decide the most optimum tasks.
(preventive or run to failure)
☑ For the accelerator maintenance
How can we apply those good point to an accelerators.

3. ・For the accelerator maintenance.
Outline
・About aircraft maintenance.
・History of the aircraft maintenance
・Before DC-8
・What is the MSG ?
・About MSG
・MSG-3 logic
・After MSG
・Comparing maintenance strategies
・Trend of the aircraft accident rate
・For the accelerator maintenance.
・How we can apply MSG to an accelerator
・Case study for cooling fans
・Accelerator task decision logic
・Conclusion

4. Maintenance concept had been changing
History of the aircraft maintenance
Maintenance concept had been changing
Overhauled
Decision logic(MSG) provide a tasks
MSG-1
MSG-3
Year
The Boeing 787
A twin-engine
Produced 2011-Present
1960
The Douglas DC-8
A four- engine
Produced
The Boeing 747
Produced 1970-Present
The Boeing 767
Produced 1982-Present
1995
1970
1975
1980
1985
1990
2000
2005
2010
2015

5. Before DC-8
overhaul or replace to new everything at specific time provided by designed life limit.
Random failure
period
Failure rate
Early failure
Wear-out failure
Bathtub curve
Time Hi
Low
Low Hi
☛ Failure rate was
cycled within early failure period.
Because, reset by overhaul
So, failure was not reduce .

6. What is the MSG ?
In 1970’s
the Maintenance Steering Group is organized with FAA, manufacturer and user .
they created logic to decide the initial maintenance tasks
the maintenance requirements decision and analysis logic which lead appropreate task.
The documentation is called MSG logic
Latest revision is MSG-3
Tasks of the MSG are classified to;
Time Control : Scheduled Preventive Maintenance
On-Conditional : Periodic Inspection. Perform corrective maintenance if failure was found.
Condition Monitor : Run to Ffailure and monitor the data trend .

7. About the MSG MSG logic consist of 3 levels analysis.
☆ Top level analysis(Assignment to MSI)
Identify aircraft’s significant systems and components .
When the failure could affect listed condition, item is assigned.
☑ safety ☑undetectable ☑significant impact
☑ significant economic impact.
☆ level-1 analysis →Determine of the failure effect.
The failure effect is categorized to:
☑ safety ☑ operational ☑ economic ☑ hidden safety
☆ level-2 analysis →Determine the appropriate task.

8. MSG-3 logic
Landing Gear wheel evaluation

9. Comparison the number of task
After MSG
☛ The aircraft structure maintenance
was shifted to on-conditional (Periodic Inspection).
747 Classis
Scheduled
Tasks
Corrosion
Prevent
Zonal
Inspection
Total
tasks
1970 MSG-1
652 54 21
727
2002 MSG-3
119
226
345
Structure
Comparison the number of task
Zonal Tasks
Time Control

10. After MSG ☛ The engine maintenance
☛ The electrical component maintenance
is shifted to Condition Monitor(Run to failure)
☛ The engine maintenance
is still Time Control
(Scheduled Preventive Maintenance)

11. Comparison of the availability analysis
Comparing Maintenance Strategies
Uptime
Average Availability= －－－－－－－
Operating Time
Run to Failure
Preventive Replacement
Mechanical Component
with wear out
Electrical Component
98%
97%
95%
Comparison of the availability analysis
Provided by RelaSoft corp.

12. Trend of an aircraft accident rate
Trend of the aircraft accident rate
The accident rate is one of parameters to indicate the aircraft reliability.
Traffic Growth 35 30 25 20 15 10 5
Departure( Millions )/Rate per millions
Accident Rate
Trend of an aircraft accident rate
MSG
2012=0.5

13. How we can apply MGS to our accelerator
Heavy Ion Medical Accelerator in Chiba, HIMAC,.
HIMAC review
・Using for research and therapy.
・ About 6,000 hours operation annually.
・More than 600 patients annually.

14. Case study for cooling fans
Background data for fans
Power supply
1. Total number of approximately 800 fans are equipped for air cooling
2. There is message if anomaly occurs
3. Those fans are replaced five years cycle
4. Removed fans showed less than critical detraction
How do you think about ?

15. Accelerator task decision logic
Yes
No, could not No
No, not affect
Could the failure affect patient and/or operator directly ?
Is there protector to protect human when failure occurs ?
Run to failure
(Condition Monitor)
Scheduled replacement
(Time Control)
Periodic Inspection
(On-Conditional)
Is there one failure affect to the immediately shut down?
Is there the message announcing the malfunction?
Is there the backup function for the defective ?
Does the failure recover in a short time ?
Does the malfunction detect by an operator before being broken?

16. Conclusion Is a maintenance money eater ? To do ・・・
Answer is
The appropriate maintenance
☑ improve the reliability
☑ save costs
☑ reduce labor
To do ・・・
☑ investigate and assess the risk.
☑ consider characteristics of component.

17. Thank you
for your attention！