Intelligent Maintenance Program Hiromi Inokuchi National Institute of Radiology Sciences, Japan e-mail : inokuchi@nirs.go.jp

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.

・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

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 1960-1972 The Boeing 747 Produced 1970-Present The Boeing 767 Produced 1982-Present 1995 1970 1975 1980 1985 1990 2000 2005 2010 2015

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 .

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 .

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.

MSG-3 logic Landing Gear wheel evaluation

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

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)

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.

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 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 35 30 25 20 15 10 5 Departure( Millions )/Rate per millions Accident Rate Trend of an aircraft accident rate MSG 2012=0.5

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.

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 ?

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?

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.

Thank you for your attention！