Aviation Maintenance Aviation Maintenance Methods:Methods:

A Proposed Multi-A Proposed Multi-Disciplinary Approach Disciplinary Approach

Gregory C. StampGregory C. Stamp

Embry-Riddle Aeronautical University Embry-Riddle Aeronautical University

14 December 200914 December 2009

2

OutlineOutline

BackgroundBackground General MaintenanceGeneral Maintenance Aviation MaintenanceAviation Maintenance Aviation Maintenance MethodologyAviation Maintenance Methodology Reliability-Centered Maintenance (RCM)Reliability-Centered Maintenance (RCM) Total Productive Maintenance (TPM)Total Productive Maintenance (TPM) Strategic Maintenance Management Strategic Maintenance Management

(SMM) (SMM) SummarySummary ReferencesReferences

3

BackgroundBackground Performance of machine will inevitably deviate from Performance of machine will inevitably deviate from

specified performance standards-leading to failures. specified performance standards-leading to failures. Driving need to minimize failures because of our Driving need to minimize failures because of our

dependence on machines dependence on machines Typical Aircraft Maintenance Program:Typical Aircraft Maintenance Program:

• Understand failure process involving functional Understand failure process involving functional and potential failures. and potential failures.

Characteristics of Modern Industrial Societies:Characteristics of Modern Industrial Societies:• Dependence on high-tech machines to produce Dependence on high-tech machines to produce

goods and services goods and services • Company productivity and outputsCompany productivity and outputs

Dependent upon the equipment’s operational Dependent upon the equipment’s operational quality quality

Various maintenance methods being implemented Various maintenance methods being implemented across several industries (e.g. transportation, across several industries (e.g. transportation, manufacturing, and mining). manufacturing, and mining).

4

General Maintenance (1 of General Maintenance (1 of 3)3)

Maintenance:Maintenance:• Definition: “A process of ensuring that a system continually Definition: “A process of ensuring that a system continually

performs its intended in level of reliability and safety” (Kinnison, performs its intended in level of reliability and safety” (Kinnison, 2004)2004)

Entropy: The “Unavailable Energy”:Entropy: The “Unavailable Energy”:• Thermodynamic concept that is used to explain the reduce Thermodynamic concept that is used to explain the reduce

designed in level of perfection of a system. designed in level of perfection of a system. • Direct correlation between entropy and required maintenance of a Direct correlation between entropy and required maintenance of a

systemsystem As entropy increases the system reliability reduces As entropy increases the system reliability reduces

dramatically, which requires increase maintenance dramatically, which requires increase maintenance Maintenance from two different perspective:Maintenance from two different perspective:

• Engineer: Primary role is the minimize entropy during system Engineer: Primary role is the minimize entropy during system designdesign

• Mechanic: Primary function is to execute preventive methods to Mechanic: Primary function is to execute preventive methods to minimize the effects of entropy of the system through its life cycle. minimize the effects of entropy of the system through its life cycle.

Two Main types of Maintenance:Two Main types of Maintenance:• Schedule Maintenance: Preventive maintenance that is executed Schedule Maintenance: Preventive maintenance that is executed

at regular time frames (e.g. daily, every 1000 cycles, etc…)at regular time frames (e.g. daily, every 1000 cycles, etc…)• Unscheduled Maintenance: Un-predictable maintenance intervals Unscheduled Maintenance: Un-predictable maintenance intervals

which may require significant effort to restore the system which may require significant effort to restore the system

5

General Maintenance (2 of General Maintenance (2 of 3) 3)

11Illustration of the natural decay of a system affecting the Illustration of the natural decay of a system affecting the systems level of perfectionsystems level of perfection

Designed in level of perfection deteriorates over time Designed in level of perfection deteriorates over time Inherent reliability of system is compromisedInherent reliability of system is compromised Corrective action needed to restore system back to original Corrective action needed to restore system back to original

levels levels

1From “Aviation Maintenance Management” by Harry A. Kinnison, 2004. Copyright 2004 by The McGraw-Hill Companies, Inc.

6

General Maintenance (3 of General Maintenance (3 of 3)3)

11Illustration of the effects of applied schedule maintenance to Illustration of the effects of applied schedule maintenance to restoring original level of perfectionrestoring original level of perfection

Schedule maintenance at optimum time period for restorationSchedule maintenance at optimum time period for restoration• Preventive maintenance is an effective means of restoring the system back Preventive maintenance is an effective means of restoring the system back

to original inherent reliabilityto original inherent reliability Extreme corrective action taken during unscheduled maintenanceExtreme corrective action taken during unscheduled maintenance

1From “Aviation Maintenance Management” by Harry A. Kinnison, 2004. Copyright 2004 by The McGraw-Hill Companies, Inc.

7

Aviation Maintenance (1 of Aviation Maintenance (1 of 2)2) Pre-World War I (WW I):Pre-World War I (WW I):

• Wright Brothers reported of one the first aircraft Wright Brothers reported of one the first aircraft maintenance discrepancies from the famous maintenance discrepancies from the famous Wright “Flyer”Wright “Flyer”

• Manufacturing simply aircraftsManufacturing simply aircrafts• Carefree attitude towards flight checks (pre/post Carefree attitude towards flight checks (pre/post

flight)flight) During WW I:During WW I:

• Early maintenance methods focused on repairing Early maintenance methods focused on repairing damages that occurred during take off and landingdamages that occurred during take off and landing

• Reliability and maintainability not high priority Reliability and maintainability not high priority while instituting a maintenance program while instituting a maintenance program

After WW II:After WW II:• Development of complex aircrafts (technology)Development of complex aircrafts (technology)• Justification of the need for preventive Justification of the need for preventive

maintenance as the complexity of machines maintenance as the complexity of machines increasedincreased

• Development of structured schedule maintenance Development of structured schedule maintenance programs to prolong the use of aircraftprograms to prolong the use of aircraft

• Unscheduled maintenance remained a significant Unscheduled maintenance remained a significant challenge for industry expertschallenge for industry experts

From www.nasa.gov/.../image_feature_976.html

From www.gereports.com/.../

8

Aviation Maintenance (2 of Aviation Maintenance (2 of 2)2)

During 1950’s:During 1950’s:• Drastic change in the perception about Drastic change in the perception about

maintenance maintenance • Implementation of maintenance techniques Implementation of maintenance techniques

viewed as critical to not only to airlines but to viewed as critical to not only to airlines but to the public in generalthe public in general

Proper maintenance inspection saves not only cost Proper maintenance inspection saves not only cost but also lives of passengers.but also lives of passengers.

• Determined previous maintenance efforts Determined previous maintenance efforts resulted in the wasting of valuable resources resulted in the wasting of valuable resources

• Safety and reliability became paramount Safety and reliability became paramount

9

Aviation Maintenance Aviation Maintenance MethodologyMethodology

(1 of 3)(1 of 3) Increasing complex systems and Increasing complex systems and subsystems in modern jetliners: subsystems in modern jetliners: • Individual mechanics effort Individual mechanics effort

becomes next to impossiblebecomes next to impossible• Comprehensive team effort neededComprehensive team effort needed

Aviation Maintenance Programs Aviation Maintenance Programs in 1960s:in 1960s:• Boeing 747 “jumbo jet” ushered in Boeing 747 “jumbo jet” ushered in

the modern era of aviation the modern era of aviation maintenance programmaintenance program

• Creation of team of subject matter Creation of team of subject matter experts to formulate possible experts to formulate possible solution to address complex solution to address complex maintenance problems maintenance problems

From www.britannica.com/EBchecked/topic-art/71246/...

10

Aviation Maintenance Aviation Maintenance MethodologyMethodology

( 2 of 3)( 2 of 3) Committee developed maintenance steering group (MSG): Committee developed maintenance steering group (MSG): • Involves several industry working groups (IWGs): structures, Involves several industry working groups (IWGs): structures,

mechanical systems, engines and auxiliary power plant, ect… mechanical systems, engines and auxiliary power plant, ect… • Considered to be a “bottom up” approach Considered to be a “bottom up” approach • Successfully applied the Boeing 747Successfully applied the Boeing 747

During the 1970s industry experts modified process to During the 1970s industry experts modified process to develop MSG-2:develop MSG-2:• Created schedule maintenance programs for Lockheed 1011 and Created schedule maintenance programs for Lockheed 1011 and

Douglas DC-10 Douglas DC-10 • MSG-2 simplifies the process to be categorized in three main areas MSG-2 simplifies the process to be categorized in three main areas

(components, structures, and engines) (components, structures, and engines) Primary objectives of the techniques outlined in MSG-1and Primary objectives of the techniques outlined in MSG-1and

MSG-2:MSG-2:• Develop a schedule maintenance program to assured the maximum Develop a schedule maintenance program to assured the maximum

safety and inherent reliabilitysafety and inherent reliability• Provide the reliability at the lowest cost Provide the reliability at the lowest cost

Used logically process flow diagram:Used logically process flow diagram:• Determine the necessary steps to resolve the maintenance issues. Determine the necessary steps to resolve the maintenance issues.

11

Aviation Maintenance Aviation Maintenance MethodologyMethodology

(3 of 3)(3 of 3) During the early 1980’s:During the early 1980’s:

• Air Transportation Association of America (ATA) created the Air Transportation Association of America (ATA) created the MSG-3 task-oriented maintenance method for the aviation MSG-3 task-oriented maintenance method for the aviation industry. industry.

Differences between MSG-3 and MSG-2 schedule Differences between MSG-3 and MSG-2 schedule maintenance:maintenance: • MSG-3 Approach- “Top- Down” instead of the “Bottom- Up” MSG-3 Approach- “Top- Down” instead of the “Bottom- Up”

approach in the MSG-2 approach in the MSG-2 • The MSG-3 also known as the “consequence of failure” The MSG-3 also known as the “consequence of failure”

approach approach • Failure analysis conducted at the “highest manageable level of Failure analysis conducted at the “highest manageable level of

the aircraft systems instead of the component level”the aircraft systems instead of the component level” United Airlines contracted to develop a more United Airlines contracted to develop a more

comprehensive approach to the MSG:comprehensive approach to the MSG:• Capability to apply schedule maintenance to other types of Capability to apply schedule maintenance to other types of

equipments and account for various shortcomings equipments and account for various shortcomings • New process created comprehensive maintenance philosophy:New process created comprehensive maintenance philosophy:

Reliability-Centered Maintenance (RCM) Reliability-Centered Maintenance (RCM) RCM: used to determine the maintenance requirement of any RCM: used to determine the maintenance requirement of any

machine machine Accounts for machines operating environmentAccounts for machines operating environment Consider this approach to be central aspect of aviation Consider this approach to be central aspect of aviation

maintenance program. maintenance program.

12

Reliability-Centered Reliability-Centered Maintenance (RCM)Maintenance (RCM)

Reliability-Centered Maintenance (RCM):Reliability-Centered Maintenance (RCM):• Systematic approach used to optimize preventive maintenance Systematic approach used to optimize preventive maintenance • RCM methodology was created in the aircraft industry as a RCM methodology was created in the aircraft industry as a

result of a number of reliability studies concerning complex result of a number of reliability studies concerning complex equipment. equipment.

RCM based maintenance program philosophy: RCM based maintenance program philosophy: • Determines requirements for any item whose loss of function or Determines requirements for any item whose loss of function or

mode of failure could have safety consequences mode of failure could have safety consequences • Develop preventive task to reduce the risk and failures Develop preventive task to reduce the risk and failures • Redesign equipment to change its failure consequences (if Redesign equipment to change its failure consequences (if

needed) needed) RCM logic categorizes four main types of failure of RCM logic categorizes four main types of failure of

consequences:consequences:• SafetySafety• Operational Costs Operational Costs • Non-operation costsNon-operation costs• Hidden Failure consequences Hidden Failure consequences

13

Total Productive Maintenance Total Productive Maintenance (TPM)(TPM)

( 1 of 2)( 1 of 2) Total Productive Maintenance (TPM):Total Productive Maintenance (TPM):

• Began in the Japanese car industry back in the Began in the Japanese car industry back in the 1970’s.1970’s.

• Considered to be a critical link in achieving Total Considered to be a critical link in achieving Total Quality Control (TQC) and Just in Time (JIT) Quality Control (TQC) and Just in Time (JIT) reductionreduction

• According to premier subject matter experts (According to premier subject matter experts (M. M. Seichi Nakajima):Seichi Nakajima):

Defines TPM as a comprehensive productive maintenance Defines TPM as a comprehensive productive maintenance that requires the total participation from everyone within that requires the total participation from everyone within the companythe company

TPM Environment: TPM Environment: • Focus on identifying and “preventing problems at Focus on identifying and “preventing problems at

the source” the source” • Creates conducive environment for managers and Creates conducive environment for managers and

line workersline workers• Incorporate a highly effective maintenance program Incorporate a highly effective maintenance program

that implements the reliability-centered maintenance that implements the reliability-centered maintenance methodology.methodology.

14

Total Productive Maintenance Total Productive Maintenance (TPM)(TPM)(2 of 2)(2 of 2) Several key TPM elements include the following: Several key TPM elements include the following:

• Maximize equipment effectivenessMaximize equipment effectiveness• Establish a in-depth preventative maintenance for the Establish a in-depth preventative maintenance for the

equipments entire life span.equipments entire life span.• Implement through various departments (i.e. engineering, Implement through various departments (i.e. engineering,

maintenance, and operations).maintenance, and operations).• Involves every single employee, from top management to workers Involves every single employee, from top management to workers

on the floor.on the floor.• Promotes preventive maintenance through motivation and Promotes preventive maintenance through motivation and

management of autonomous small group activitiesmanagement of autonomous small group activities TPM Impacts: TPM Impacts:

• Bottom-line by revitalizing and enhancing quality management Bottom-line by revitalizing and enhancing quality management approach. approach.

• Integration with RCM Integration with RCM • Outcomes -improved capacity and reducing both maintenance Outcomes -improved capacity and reducing both maintenance

cost and overall operational costs (Kennedy, 1996).cost and overall operational costs (Kennedy, 1996). Comparison to RCM:Comparison to RCM:

• TPM seen as more management oriented TPM seen as more management oriented • RCM is oriented towards engineering level tasks RCM is oriented towards engineering level tasks • RCM handles the preventative maintenance standard RCM handles the preventative maintenance standard • TPM establishes the overall company mindset for continuous TPM establishes the overall company mindset for continuous

improvement improvement

15

Strategic Maintenance Strategic Maintenance Management (SMM)Management (SMM)

Strategic Maintenance Management (SMM): Strategic Maintenance Management (SMM): • Focuses on the long-term strategic issues of the company Focuses on the long-term strategic issues of the company • Differs from narrow (short-term) operating context observed in the Differs from narrow (short-term) operating context observed in the

RCM RCM and TPM and TPM • Forms an integral part of the management processForms an integral part of the management process

Two key elements of SMM methodology are the following:Two key elements of SMM methodology are the following:• Maintenance management is a vital core business activityMaintenance management is a vital core business activity

Critical to business survival and success Critical to business survival and success • Effective maintenance management needs to be based on Effective maintenance management needs to be based on

quantitative business modelsquantitative business models Integrate maintenance with other decisions such as production Integrate maintenance with other decisions such as production

Overall effective maintenance management involves:Overall effective maintenance management involves:• Formulating maintenance strategies Formulating maintenance strategies • Implementing these strategies for business success companies Implementing these strategies for business success companies

Multi-Disciplinary Approach: Multi-Disciplinary Approach: • Integration with both traditional TPM and RCM methodologies is Integration with both traditional TPM and RCM methodologies is

possiblepossible• Compliments existing policies by providing strategic focus and Compliments existing policies by providing strategic focus and

perspective perspective • Applied to overall company maintenance strategies with SMMApplied to overall company maintenance strategies with SMM• Modern effective maintenance management program requires a Modern effective maintenance management program requires a

multi-disciplinary approach (strategic approach to maintenance) multi-disciplinary approach (strategic approach to maintenance)

16

Summary Summary Pervasive Presence of Machines:Pervasive Presence of Machines:

• Indicates our reliance on machines ease some of tedious Indicates our reliance on machines ease some of tedious burdensburdens

• Expected system degradations and failuresExpected system degradations and failures Developed Several Methods:Developed Several Methods:

• Systematical approach these imperfections. Systematical approach these imperfections. • Reliability Centered Maintenance (RCM) involves a logical Reliability Centered Maintenance (RCM) involves a logical

approach to preventive maintenance (RCM). approach to preventive maintenance (RCM). • Total Productive Maintenance (TPM) involves each employee Total Productive Maintenance (TPM) involves each employee

in the continuous improvement process.in the continuous improvement process.• Strategic Maintenance Management (SMM) involves top-Strategic Maintenance Management (SMM) involves top-

level management incorporate maintenance in the level management incorporate maintenance in the company’s strategic planning by supporting a methodology. company’s strategic planning by supporting a methodology.

Multi-Disciplinary Approach:Multi-Disciplinary Approach: • Incorporates RCM, TPM, and SMM in a maintenance Incorporates RCM, TPM, and SMM in a maintenance

program program • Capable of improving the overall effectiveness of the Capable of improving the overall effectiveness of the

companycompany Reduces operational and maintenance cost as well as improve Reduces operational and maintenance cost as well as improve

productivityproductivity Strive to minimize failures and save livesStrive to minimize failures and save lives

17

ReferencesReferences

American Psychological Association. (2001). Publication Manual of the American American Psychological Association. (2001). Publication Manual of the American Psychological Association (5th ed.). Washington, DC.: American PsychologicalPsychological Association (5th ed.). Washington, DC.: American Psychological Association. Association. Ben-Daya, Mohammed. (2000). You may need RCM to enhance TPM implementation. Ben-Daya, Mohammed. (2000). You may need RCM to enhance TPM implementation. Journal of Quality in Maintenance, 6, 2, 82-85.Journal of Quality in Maintenance, 6, 2, 82-85.Cobb, T. W. (2005). Aircraft Maintenance Management (2nd ed.). Florida: Embry-Cobb, T. W. (2005). Aircraft Maintenance Management (2nd ed.). Florida: Embry-

RiddleRiddle Aeronautical University Aeronautical University Kennedy, R. (1996). Examining the process of RCM and TPM: What do they ultimately Kennedy, R. (1996). Examining the process of RCM and TPM: What do they ultimately

achieve achieve and are the two approaches compatible? [Electronic Version]. Retrieved and are the two approaches compatible? [Electronic Version]. Retrieved

December, 3December, 3 2009 from The Centre of Total Productive Maintenance (TPM)-Australasia. 2009 from The Centre of Total Productive Maintenance (TPM)-Australasia. Kinnison, H. A. (2004). Aviation Maintenance Management. New York: The McGraw-Kinnison, H. A. (2004). Aviation Maintenance Management. New York: The McGraw-

Hill Hill Companies. Companies. Lahiri, R.N., Sinha, A. Chowdhury, S., Chowdhury, S.P., Crossley, P.A. (2008). Lahiri, R.N., Sinha, A. Chowdhury, S., Chowdhury, S.P., Crossley, P.A. (2008).

Importance of Importance of strategic maintenance management for Indian utility industry [Electronic strategic maintenance management for Indian utility industry [Electronic

Version]. Version]. Retrieved December, 3 2009 from IEEE Xplore. Retrieved December, 3 2009 from IEEE Xplore. Matteson, T.D., & Nowlan, F.S. (1967). Current trends in airline maintenanceMatteson, T.D., & Nowlan, F.S. (1967). Current trends in airline maintenance programs. American Institute of Aeronautics and Astronautics, 67-379. programs. American Institute of Aeronautics and Astronautics, 67-379.

18

ReferencesReferencesMurthy, D.N.P., Atrens, A., Eccleston, J.A. (2002). Strategic Murthy, D.N.P., Atrens, A., Eccleston, J.A. (2002). Strategic

maintenance management.maintenance management. Journal of Quality in Maintenance, 8, 4, 287-305. Journal of Quality in Maintenance, 8, 4, 287-305. Nowlan, F.S. (1978). Preventive maintenance- past, present, Nowlan, F.S. (1978). Preventive maintenance- past, present,

and future. American Institute of and future. American Institute of Aeronautics and Astronautics, 78-1529.Aeronautics and Astronautics, 78-1529.Perotti, G. (n.d). Maintenance integrated system: The right Perotti, G. (n.d). Maintenance integrated system: The right

recipe of TPM and RCM recipe of TPM and RCM [Electronic Version]. Retrieved December, 3 2009 from [Electronic Version]. Retrieved December, 3 2009 from

http: // www.terosonline.it http: // www.terosonline.it Reyes-Picknell, J. (2006). RCM vs. TPM: Which is best? Reyes-Picknell, J. (2006). RCM vs. TPM: Which is best?

[Electronic Version]. Retrieved December, 3 2009 from [Electronic Version]. Retrieved December, 3 2009 from http://uptimethebook.blogspot.com/2006/07/rcm-vs-tpm-http://uptimethebook.blogspot.com/2006/07/rcm-vs-tpm-which-which-

works-best.htmlworks-best.html

19

Any Questions?Any Questions?