Reducing the Turnaround Time of In House Repairs of Aircraft Engine MRO Services

147 Pages·2016·20.14 MB·English

Reducing the Turnaround Time of In
House Repairs of Aircraft Engine MRO
Services
A Case Study at KLM Engineering and Maintenance Engine Services
by
P.C.M. (Pien) Meijs
4009428
TIL5060-MasterThesisProject
DelftUniversityofTechnology
MSc. Transport,InfrastructureandLogistics
April2016

Reducing the Turnaround Time of In
House Repairs of Aircraft Engine MRO
Services
A Case Study at KLM Engineering and Maintenance Engine Services
TIL5060 - Master Thesis Project
ForthedegreeofMasterofScienceinTransport,InfrastructureandLogistics
attheDelftUniversityofTechnology
by
P.C.M. (Pien) Meijs
4009428
Date: April14,2016
TobedefendedonApril28,2016,14hr00,
LectureRoom’EmileTruijen’,
FacultyofIndustrialDesignEngineering
Reportnumber: 2016.TIL.8024
GraduationCommittee:
prof.dr.ir.G.Lodewijks Chair TUDelft,faculty3ME
dr.W.W.A.BeelaertsvanBlokland Supervisor TUDelft,faculty3ME
dr.ir.J.H.Baggen Supervisor TUDelft,facultyCiTGandTPM
G.PhilipsvanBuren ExternalSupervisor KLMEngineeringandMaintenance
A.Gortenmulder ExternalSupervisor KLMEngineeringandMaintenance

Preface
Thousands and thousands of flights are carried out every day and even millions of people are
transported through the air. For a lot of people this is business as usual; they have been on
a plane for multiple times and use it for business or leisure purposes. Despite the fact that
so many people are using a plane as a way of transportation, only a few people are aware of
the complexity of the associated maintenance of the aircraft. During my graduation project at
KLM Engineering and Maintenance I got the unique opportunity to become familiar with the
maintenanceofaircraft.
Theresultofthisprojectispresentedinthereportlyinginfrontofyou. Withthismasterthesis
projectIcompletemymasterstudiesTransport,InfrastructureandLogistics(TIL)andIconclude
mytimeasastudentattheDelftUniversityofTechnology. Iconductedmymasterthesisproject
at the Lean Six Sigma Office of KLM Engineering and Maintenance. The project focuses on
improving the performance of the KLM Engine Services at Amsterdam Airport Schiphol. This
reportpresentsfactorsthatinfluencetheturnaroundtimeofinhouserepairsofaircraftengine
MROservices. Moreoverthereportassessesdifferentalternativesthatinfluencethesefactors
in order to reduce the turnaround time. The alternatives are selected based on findings in
literature and the case study at the Engine Services. Both the factors and the alternatives are
presentedanddiscussedinthisreport.
I could not have completed this master thesis project without the help of others. Therefore I
wouldliketousethisopportunitytothankthesepeople.
Firstofall,IwouldliketothankGuusPhilipsvanBurenenAlexGortenmulderforgivingmethe
opportunitytoconductmymasterthesisatKLME&Mandfortheirhelpandfeedbackduringthe
project. IalsowanttothankallmycolleaguesatEngineServicesfortheirtime,informationand
help. MoreoverIwanttothankmygraduationcommittee,Gabrie¨lLodewijks,WouterBeelaerts
van Blokland and John Baggen, for their supervision, input and critical questions during my
masterthesisproject. BesidesIwouldliketothankRoeland,JobenArjanfortheir”gezelligheid”
andtheendlessamountoftablefootballmatches. Andlast,butdefinitelynotleast,Iwouldlike
tothankmyfamilyandfriendsfortheirsupportandforthedistractionwhenneeded.
Hopeyouenjoyreadingmythesis.
Delft,April14,2016
PienMeijs
iii

Management Summary
The aircraft engine MRO market is changing. The customers are increasingly demanding due
tofiercecompetitionasaresultofthegrowingnumberofairlines. Thereforethecustomersare
lookingforfasterandcheaperMROservicesofhighquality. Moreoverthecompetitionbetween
theMROprovidersisfierceasaresultofthehighnumberofcompaniesofferingMROservices.
In order to maintain or increase their market share, MRO providers have to offer quick and
cheapmaintenanceofhighquality. MROprovidersthereforeneedtochangethewaytheywork
andofferfasterandcheaperservicesofhighquality,butcurrentlyitisstillunknownhow.
KLM E&M is the perfect case study for this research topic because of the following reasons.
First, KLME&Mstatesitistoocomplex, tooslowandtooexpensivetoupdatetheirprocesses
smoothly. Moreover, in 2015 KLM E&M Engine Services delivered only 43% of the engines
on time. Besides, KLM E&M is also not market leading in terms of turnaround time and costs.
Therefore KLM E&M needs to change her way of working. However, how KLM E&M needs to
changeherwayofworkingisstillunclear.
This research focuses on reducing the turnaround time of the in house repairs of full shop
visits. In order to reduce the turnaround time, this research aims to determine the factors that
influence the turnaround time of in house repairs of aircraft engine MRO services, to identify
a set of alternatives to reduce the turnaround time of the repairs and to present their impact
on the performance of the aircraft engine MRO services, based on a case study at KLM E&M
Engine Services. Herewith this research answers the main question of this research: Which
alternatives can be identified in order to reduce the turnaround time of the in house repairs of
aircraft engine MRO services and what is the impact of these alternatives on the performance
ofthesystem?
LiteratureReview
Theliteraturereviewpresentsdifferentmethodsforprocessimprovementinordertofindfactors
that influence the turnaround time of in house repairs. The analyzed methods are Business
ProcessManagement,Lean,SixSigma,LeanSixSigmaandtheTheoryofConstraints.
Thefindingsfromliteraturecanbesummarizedinaliteratureframework. Thisframeworkcon-
sistsoffourconditions,namely: processfocused,end-to-endprocess,continuousimprovement
and insight intothe customer value. Without fulfillingthese conditions, solutions will alwaysbe
sub-optimal. Next, there are multiple factors influencing the turnaround time. These factors
can be divided in two categories: waste and assets and resources. The category waste con-
sists of transport, inventory, motion, waiting, overprocessing, overproduction and defects and
v
vi ManagementSummary
rework. Thecategoryassetsandresourcesconsistsoftheavailabilityofman,theavailabilityof
material,theavailabilityofmethods,theavailabilityofmachines andthebatchsize.
CaseStudyatKLME&M
Next a case study is performed in order to assess the factors found in literature to practice.
The case study is performed at KLM E&M and focuses on the in house repairs that are part
of the full shop visits at the Engine Services. The in house repairs are performed on several
specialized workstations. The fanblades workstation performs worst regarding the turnaround
timeoftherepairs. Currently,only29%ofthecompletesetsoffanbladesaredeliveredontime.
Theaverageturnaroundtimeis40daysandmainlyconsistsofwaitingtimes. 74%ofallwaiting
timesiscausedbyfourtechniekcodes,namely:
• Q504: ShotpeeningOverall
• Q810: BenchworkAirfoils
• Q811: SealReplacement
• Q813: Insp/prts/repFanblades
These waiting times are mainly caused by inventory, waiting, overprocessing, rework, the lack
ofavailabilityofmachines,thelackofavailabilityofmanandthebatchsize.
FactorsofInfluence
WhencombiningthesefindingsfromthecasestudyatKLME&Mwiththefindingsofthelitera-
turereview,itcanbeconcludedthatnotallfactorsthatinfluencetheturnaroundtimeaccording
to the literature, actually have a strong impact on the turnaround time of the in house repairs
of engine MRO services. As only the factors that have a strong influence on the turnaround
timeoftheinhouserepairsofengineMROservicesareinteresting,theliteratureframeworkis
updatedintoacurrentstateframework,whichisdepictedinthefigurebelow.
ManagementSummary vii
It can be seen that only seven factors of influence are included in the current state framework.
ThesefactorsarestillacombinationofBusinessProcessManagement,Lean,SixSigma,Lean
SixSigmaandtheTheoryofConstraints. Thereforethiscurrentstateframeworkcanstillfunc-
tionasatoolforthecombinedimplementationofthedifferentprocessimprovementmethods.
PerformanceMeasurement
The case study shows that the current performance measurement of the in house repairs of
engine MRO services at KLM E&M is not sufficient for measuring the performance of the fan-
bladesworkstation. First,notthecompleteprocessistakenintoaccount. Moreoverthecurrent
performance indicator does not measure the performance of a complete set of fanblades. A
new performance indicator is introduced in order to measure the performance of the complete
processforacompletesetoffanblades:
TATi =CompleteSeti −CompleteSeti (1)
CompleteSet end start

1, ifTATi ≤33
CompleteSeti = CompleteSet (2)
OnTime
0, otherwise
(cid:80) CompleteSeti
TAT = i∈I OnTime ∗100% (3)
performance n
with:
TATi =TurnaroundTimeofthecompleteseti[day]
CompleteSet
CompleteSeti =Finishdayofaseti[day]
end
CompleteSeti =Startdayofaseti[day]
start
TATperformance=%ofcompletesetsoffanbladesdeliveredontime[%]
I =Setofallsetsoffanblades
n=NumberofcompletesetsinsetI [#]
Next to the performance indicator on the turnaround time, also performance indicators within
the process are needed in order to early notice deviations in the process and to be able to
localizetheproblemsintheprocess. Theperformancewithintheprocessneedstobemeasured
usingthesetofprocessperformanceindicatorsoninventory, waiting, overprocessing, rework,
availabilityofmachines,availabilityofmanandbatchsize.
SetofAlternatives
A set of 12 different alternatives is designed in order to reduce the turnaround time. These
alternatives influence the main problem areas on the factors of influence. The alternatives
are assessed on five criteria using a Multi-Criteria Analysis (MCA). The assessment criteria
are turnaround time, process costs, implementation costs, quality of the product and ease of
implementation.
Based on the criteria the MCA selected five alternatives that influence the performance of the
systembest. Thesealternativesare:
viii ManagementSummary
• A1: AdvancedOperatorPlanning
• A3: CombiningShotpeenCapacity
• A6: Self-Inspections
• A10: BatchSizeof8Fanblades
• A12: Drum,buffer,rope
At the moment the average turnaround time of the system is 40 days. The implementation of
the selected alternatives results in a turnaround time of 16.4 days. Thus, on average all sets
of fanblades will be delivered on time. Looking at the data set used for this research, currently
only29%ofthesetsoffanbladesisdeliveredontime. Afterimplementingthealternatives,98%
ofallsetsoffanbladesisdeliveredontime.
RecommendationsforScience
From a scientific perspective it is recommended to perform multiple case studies in order to
validate the framework containing the factors of influence as currently the framework is based
on the findings of only one case study. First of all, it is interesting to perform another case
study within KLM E&M Engine Services. Next, it is also interesting to perform a case study at
another engine MRO service provider or a company in another MRO business. It is expected
thattheframeworkwillbespecificallyusefulforprocessesthatcontainsharedresources,work
withlargebatchesofpartsandhavesimilarworkscopes.
RecommendationsforKLME&M
For KLM E&M Engines Services it is recommended to directly implement the new way of per-
formancemeasurementatallworkstationsintheengineshop. Thiswaymanagerscanquickly
notice and localize irregularities in the process and thus intervene fast and effective. The new
wayofperformancemeasurementcanonlybeimplementedwhenthewayofdatacollectionis
more precise. It is requiredto note the exact starting and finish moment ofthe task. Moreover
thepreciseset-uptimes,processingtimesandwaitingtimesarerequired.
Nexttothenewwayofperformancemeasurement, itisrecommendedtofirstimplementalter-
nativesA1,A3,A6andA10. AlternativeA12shouldbeimplementedaftertheotheralternatives
are implemented. However, before the alternatives are implemented, it is important do more
in-depth research on the costs and the benefits of the alternatives as the current numbers are
based on estimates. Moreover it is advised to organize an action-workout session when im-
plementing the alternatives. This way the employees can be involved in the process and the
implementationcanbekick-started. Thisworkoutsessioncanalsobeusedtoorganizeapilot
forthealternativesinordertotestthepotentialofthealternativesagain.
Finally, it is interesting to look for opportunities to introduce the different alternatives at other
workstations. The alternatives will be specifically interesting for the workstations that contain
sharedresources,workwithlargebatchesofpartsandhavesimilarworkscopes.