Xu, Yuchun; Feng, Wei
A icle
De elop a cos model o e alua e he economic bene i o
emanu ac u ing based on speci ic echnique
Jou nal o Remanu ac u ing
P o ided in Coope a ion wi h:
Sp inge Na u e
Sugges ed Ci a ion: Xu, Yuchun; Feng, Wei (2014) : De elop a cos model o e alua e he economic
bene i o emanu ac u ing based on speci ic echnique, Jou nal o Remanu ac u ing, ISSN
2210-4690, Sp inge , Heidelbe g, Vol. 4, Iss. 4, pp. 1-12,
h ps://doi.o g/10.1186/2210-4690-4-4
This Ve sion is a ailable a :
h ps://hdl.handle.ne /10419/155493
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RESEARCH Open Access
De elop a cos model o e alua e he
economic bene i o emanu ac u ing based
on speci ic echnique
Yuchun Xu
*
and Wei Feng
* Co espondence:
[email p o ec ed]
School o Applied Sciences,
C an ield Uni e si y, C an ield,
Bed o d MK43 0AL, UK
Abs ac
Remanu ac u ing is a p ocess o eco e ing used p oduc s o a like-new condi ion. I
can po en ially achie e conside able economic, en i onmen al and social bene i s in
many applica ions. Howe e , i s economic bene i a ies o di e en p oduc s and
emanu ac u ing p ocesses. This esea ch aims o de elop a amewo k and cos
model o quan i a i ely e alua e he bene i s o emanu ac u ing echniques o
assis he decision making on end-o -li e s a egies. Addi i e manu ac u ing-based
emanu ac u ing p ocess has been modelled i s , hen cos b eakdown s uc u e o
he p ocess has been c ea ed, and he cos model has been de eloped. Valida ion o
he cos model has been conduc ed based on expe judgemen , and a case s udy
has been ca ied ou by using he de eloped cos model o compa e he bene i o
emanu ac u ing a speci ied componen o making a new one.
Keywo ds: End o li e; Remanu ac u ing; P oduc eco e y; Cos es ima ion;
Cos enginee ing; Economic bene i analysis
1 In oduc ion
Remanu ac u ing is a p ocess o eco e ing he used p oduc s o a like-new condi ion
[1]. I enables he cus ome s o ha e p oduc s in lowe cos and also enables he man-
u ac u e s o sa e aw ma e ials and o he p oduc ion cos s. Remanu ac u ing can po-
en ially achie e conside able economic, en i onmen al and social bene i s.
In some high- ech indus ial sec o s, e.g. ae ospace, emanu ac u ing is an app o-
p ia e s a egy o be adop ed because (1) high- alue pa s a e well wo h o keep
i possible and s ill mee sa e y equi emen s; (2) P oduc Se ice Sys em (PSS)
business model is widely adop ed by some manu ac u e s, such as he ae o engine
manu ac u e s Rolls-Royce Plc. and Gene al Elec ic (GE), which makes emanu-
ac u ing possible because he used p oduc s a e owned by he o iginal manu ac-
u e s in he PSS model, and he logis ic channel and cus ome ela ionships a e
ela i ely ma u e and (3) new echniques p o ide po en ial ways o emanu ac u e
high- alue pa s.
Despi e he po en ial bene i s, emanu ac u ed p oduc s s ill accoun a ela i ely
small po ion compa ed o new manu ac u ed p oduc s in gene al. One o he easons
is he economic bene i o emanu ac u ing is no clea when conside ing a ie y o
© Xu and Feng; licensee Sp inge . This is an open access a icle dis ibu ed unde he e ms o he C ea i e Commons
A ibu ion License (h p://c ea i ecommons.o g/licenses/by/2.0), which pe mi s un es ic ed use, dis ibu ion, and ep oduc ion in any
medium, p o ided he o iginal wo k is p ope ly ci ed.
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2014
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p oduc s o be emanu ac u ed and a ie y o emanu ac u ing p ocesses ha can be
used.
Some p e ious esea ch ha e de eloped me hods o assess emanu ac u ing and o he
end-o -li e op ions in economic, en i onmen al and social aspec s. Fo example, he de-
cision making app oach has been used by a numbe o esea che s. Dunmade in o-
duced a sus ainabili y-based app oach o e alua ing emanu ac u ing and o he
p oduc eco e y p ocesses, which named ‘p oduc li ecycle ex ension echniques selec-
ion (PLETS)’model. This model designed by uzzy logic and mul i-a ibu e decision
can sco e each p oduc eco e y p ocess agains he selec ed c i e ia [2]. Bu a di e al.
p oposed a mul i-c i e ia decision aid (MCDA) app oach o help manu ac u e s selec
sui able p oduc s o end-o -li e al e na i es ( emanu ac u ing o o he p oduc
eco e y p ocesses) [3]. Jun e al. de eloped a mul i-objec i e algo i hm o e alua e
he end-o -li e al e na i es including emanu ac u ing [4]. Fe nández e al. de el-
oped a uzzy algo i hm o selec p oduc eco e y policies. In ha algo i hm, p od-
uc cha ac e is ics such as p oduc alue, olume, use ul li e and cus ome
cha ac e is ics (such as cus ome loca ion) a e conside ed as he a iable ac o s
[5]. Iako ou e al. designed he ‘Mul ic i e ia Ma ix’me hodology o decision
making in end-o -li e al e na i es. Mul i-c i e ia analysis was pe o med based on he
esidual alue, en i onmen impac , weigh , quan i y and ease o disassembly [6]. Ghazalli
and Mu a a de eloped an analy ical hie a chy p ocess (AHP) wi h case-based easoning
(CBR) app oach o suppo end-o -li e s a egy selec ion. The economic cos and en i on-
men al cos we e selec ed as he e alua ion c i e ia [7]. Jiang Z e al. [8] p oposed a mul i-
c i e ia decision making (MCDM) model o selec ing emanu ac u ing echnology, he
pai -wise compa ison app oach o he analy ic hie a chy p ocess (AHP) was employed o
he emanu ac u ing echnology po olio selec ion.
Resea ch has also been ound pa icula ly o assessing he economic bene i o
emanu ac u ing and o he end-o -li e (EoL) op ions. Chen and Chang esea ched he
economics o a closed-loop supply chain (CLSC) inco po a ing emanu ac u ing
based on a news endo amewo k bea ing case. The economic analysis was ca ied
ou a high le el o he hyb id sys em (including bo h manu ac u ing and CLSC and
emanu ac u ing) o suppo decision making a emanu ac u ing sys em le el [9].
Su he land e al. p esen ed a cos model a sys em le el, and he model is used o
op imise he emanu ac u ing acili y size. The model did no conside he a ia ion
o emanu ac u ing me hods, i was no able o op imise he selec ion o EoL s a -
egies [10]. Azadi a and O doobadi es ima ed he cos o emanu ac u ing a high
le el by aking in o accoun he assembly cos , disassembly cos , in en o y cos and
disposal cos . The cos es ima ion was mo e ocused on how o model he lo size o
emanu ac u ing and build he impac o lo size in he cos es ima ion, and i did
no conside he di e ence be ween di e en emanu ac u ing echnologies and
p ocesses [11].
F om he abo e- e iewed esea ch, mos o e alua ion and cos es ima ion o ema-
nu ac u ing and EoL op ions a e conduc ed a high le el (EoL s a egy le el); how-
e e , esea ch on e alua ing emanu ac u ing based on speci ic echniques and
p ocesses emains limi ed. This pape p esen s a s udy on how eliable cos es ima-
ion o emanu ac u ing can be ealised by cos modelling a de ailed echniques
and p ocess le els.
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2 Remanu ac u ing p ocess modelling
In his esea ch, he in es iga ed emanu ac u ing p ocess is based on addi i e manu-
ac u ing echnique, which deli e s a wi e o he wo king a ea and he wi e is hea ed
and mel ed and e en ually deposi ed in o he wo king a ea. This emanu ac u ing
p ocess consis s o ou phases, which a e e e se enginee ing, da a p ocessing, deposi -
ing and g inding, as can be seen in Figu e 1.
In Figu e 1, he e e se enginee ing phase is o iden i y wha a eas/ ea u es o eman-
u ac u e. I consis s o he ollowing s eps:
1) Re u ned p oduc s a e measu ed by high- esolu ion digi al came as o any o he
con ac o non-con ac app oach o build up he digi al geome y o used pa .
2) The digi al geome y o he used pa is compa ed wi h a e e ence model o
iden i y he di e ence in geome y.
The da a p ocessing phase includes ou ac i i ies: gene a ing econs uc ion speci i-
ca ion, gene a ing machining speci ica ion, gene a ing ool pa h in he emanu ac u ing
machine ool and simula ing ool pa h. The econs uc ion speci ica ion is ans o med
in o machining speci ica ion, and hen he ool pa h is gene a ed. Simula ion is con-
duc ed o p e-check he emanu ac u ing p ocess a he beginning. The da a p ocessing
s ep is no mally ca ied ou semi-au oma ically.
Remanu ac u ing P ocess
Da a P ocessing deposi in Gg indingRe e se Enginee ing
Tool Pa h
Gene a ing
Machining
Speci ica ion
Gene a ing
Se up
Adding ma ei als
G inding
Check Gas &
Wi es
Check
G inding
Wheel
Fill Gas / Wi es
Replace G inding
Wheel
No enough
Enough
No enough
Remanu ac u ed
Componen
End-o -li e
Componen
Geome y
Digi izing
Compa ison wi h
Re e ence Model
Quali y G ading
Remanu ac u a-
bili y Check
Reuse, Recycle o
Sc ap
N
Recons uc ion
Speci ica ion
Gene a ing
Y
Tool Pa h
Simula ion
Enough
Figu e 1 Addi i e manu ac u ing-based emanu ac u ing p ocess model.
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The machining p ocess consis s o wo phases, which a e deposi ing phase and g ind-
ing phase. The deposi ing phase includes se up, gas/wi e check and adding ma e ials;
he g inding phase includes g inding wheel check and g inding p ocess i sel . Excep
he se up, o he machining p ocesses a e ope a ed au oma ically.
3 Cos model de elopmen
The cos model in his s udy was de eloped by ollowing he cos es ima ion p ocess
sugges ed by he NASA Cos Es ima ing Handbook [12]. The key s eps a e explained in
he ollowing sec ions.
3.1 Cos es ima ion me hodology selec ion
An app op ia e cos es ima ing me hodology needs o be selec ed i s . The a ailable
cos es ima ing me hodologies, such as pa ame ic es ima ion [13-17], enginee ing
build up es ima ion [18-22,16,23,17], analogy-based es ima ion and endo quo es es i-
ma ion [13,16], a e compa ed in e ms o equi ed ime, equi ed esou ce, equi ed
da a and scope o applica ions, as shown in Table 1. Le e H, M and L ep esen high,
medium and low le el o each e m, espec i ely.
Fo he emanu ac u ing p ocess based on addi i e manu ac u ing echnique,
he e is no eady a ailable his o y cos da a abou his p ocess, so i is impos-
sible o use pa ame ic cos es ima ion me hod. Also, he e is no simila alid
emanu ac u ing cos es ima ion cases based on addi i e manu ac u ing ech-
nique, hus analogy-based es ima ion and endo quo es es ima ion a e no sui -
able in his s udy. Conside ing he da a and esou ce a ailable, enginee ing
build-up cos es ima ion me hod has been selec ed o de eloping he cos es i-
ma ion model in his s udy.
3.2 Cos b eakdown s uc u e de elopmen
The cos elemen associa ed wi h he emanu ac u ing p ocess has been iden i ied ac-
co ding o he p ocess modelled. This iden i ica ion p ocess complies wi h he mu ually
exclusi e and collec i ely exhaus i e (MECE) p inciple, which means elemen s in he
cos b eakdown s uc u e (CBS) should ha e ‘no o e laps’and ‘no gaps’[24]. The whole
CBS is like a solid ‘py amid’wi hou any omission and duplica ion.
Acco ding o his guideline below, he p ocess is ollowed o CBS es ablishmen .
The i s s ep is o de ine he i s le el o he CBS, his le el co e s all he majo ele-
men s o he o al emanu ac u ing cos , and also ha e no dependency be ween each
o he . A e ha , he lowe le els o he CBS a e de eloped based on he same p inciple
un il he le el whe e cos alue can be collec ed di ec ly o calcula ed h ough he de-
ailed emanu ac u ing p ocess in o ma ion. The CBS de eloped in his s udy is shown
Table 1 Fea u es o cos es ima ing me hodologies
Time needed Resou ce needed Da a needed Scope o he me hod
Pa ame ic es ima ion M M M M
Enginee ing build up es ima ion H H H H
Analogous es ima ion L M H L
Vendo quo es es ima ion L L L L
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in Figu e 2. As can been seen om i , he emanu ac u ing p ocess includes h ee cos
elemen s in he i s le el: p e-p oduc ion cos , p oduc ion cos and o e head cos .
1) P e-p oduc ion cos : P e-p oduc ion cos includes e e se enginee ing cos and da a
p ocessing cos ; bo h a e labou -in ensi e cos s and can be calcula ed by labou
hou ly a e and equi ed wo king ime.
2) P oduc ion cos : P oduc ion cos has been di ided in o h ee cos elemen s: se up
cos , deposi ing cos and g inding cos . Se up cos is he labou cos o inpu ing
he manu ac u ing speci ica ion, speci ying he ool pa h and clamping he
componen s on o he machine able. Deposi ing cos and g inding cos a e
machine- ela ed cos s, hey can be di ided in o ma e ial cos , consumable cos
(such as shielding gas cos , wheel eplacemen cos , cooling liquid cos , e c.),
Remanu ac u ing
Cos Deposi ing Cos
G inding Cos
Labo Cos
Shielding Gas
Cos
Ma e ial Cos
Deposi ing
Machine
Dep ecia ion
Powe Cos
G inding Machine
Dep ecia ion
Wheel
Replacemen Cos
Powe Cos
Cooling Liquid
Labou Cos
Labo Cos
Labo Cos
Labou Cos
O e head Cos Machine
Main enance Cos
Adminis a ion
Cos
O he O e head
Cos
P e-p oduc ion
Cos
P oduc ion Cos
Se upCos
Re e se
Enginee ing Cos
Da a P ocessing
Cos
Figu e 2 Cos b eakdown s uc u e o emanu ac u ing p ocess.
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machine dep ecia ion cos , powe cos and labou cos . Mos o hem (excep
ma e ial cos ) a e unc ions o ope a ion ime.
3) O e head cos : The las cos elemen in he i s le el o he CBS is o e head cos . I
includes adminis a ion cos , machine main enance cos and o he o e head cos , such
as ligh ing, insu ance cos , e c. As o e head cos is indi ec cos , i a ies by cases.
3.3 Cos d i e iden i ica ion
Cos d i e s a e hose a ibu es o emanu ac u ing p ocess ha a ec he cos o he
di e en ac i i ies in emanu ac u ing p ocess. The cos d i e s ha e been mainly
iden i ied based on he in o ma ion ga he ed om he au ho 's knowledge, e iewed li -
e a u e and in e iewed ield expe s. The main cos d i e s o each phase o emanu-
ac u ing p ocess a e lis ed in Table 2.
3.4 Cos es ima ion ela ionships de elopmen
Cos es ima ion ela ionships (CERs) need o be de eloped o each cos elemen in he
CBS using he iden i ied cos d i e s. I means ha each cos elemen is exp essed as a
unc ion o he cos d i e s. Fo example he labo cos o deposi ing and g inding
p ocess is calcula ed as below:
Cl¼RlTwþTg
 ð1Þ
whe e C
l
is he labou cos (£), R
l
is he labou hou ly a e (£/h) and T
w
and T
g
a e he
imes o deposi ing p ocess and g inding p ocess, espec i ely.
Tw¼Td
1−iw
¼Md
D1−iw
ðÞ ð2Þ
Tg¼T m
1−ig
¼Mg
R1−ig
 ð3Þ
whe e T
d
and T
m
a e he deposi ion ime in deposi ing p ocess and ma e ial emo al
ime in g inding p ocess (h), i
w
and i
g
a e he idle a e o deposi ing and g inding p o-
cesses (%), Dis he deposi ion a e o deposi ing machine (kg/h), Ris he emo al a e
o g inding machine (kg/h).
In summa y, he o al cos o emanu ac u ing is calcula ed by agg ega ing all he cos
elemen s:
C o al ¼Cp e þCse þCwþCsþCgþCdþClþCpþCoð4Þ
whe e C
o al
is he o al cos o emanu ac u ing, C
p e
is he p e-p oduc ion cos , C
se
is
he se up cos in he p oduc ion s age, C
w
,C
s
and C
g
a e he cos o deposi ing ma e ial,
Table 2 Main cos d i e s o emanu ac u ing p ocess
Remanu ac u ing p ocesses Cos d i e s
Re e se enginee ing Complexi y o he shape o emanu ac u e
Da a p ocessing Complexi y o he shape o emanu ac u e
Deposi ing Volume o he pa o emanu ac u e
Complexi y o he shape o emanu ac u e
G inding Volume o he pa allowance o emo e
Complexi y o he shape o emanu ac u e
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shielding gas cos and g inding wheel consump ion cos in he p oduc ion s age, C
d
,C
l
,
C
p
and C
o
a e he machine dep ecia ion cos , labou cos , powe cos in he p oduc ion
s age and o e head cos , espec i ely.
3.5 P ocess pa ame e s iden i ica ion
The pa ame e s o he emanu ac u ing p ocess depend on he inpu pa ame e s o
emanu ac u ing and a e de e mined by a knowledge base, which s o es he ela ion-
ship be ween hese wo se s o pa ame e s. This knowledge base is designed p e iously
based on he op imiza ion esul s o expe imen s and he expe s' expe iences; his con-
cep is shown in Figu e 3.
The p ocess pa ame e s include deposi ion cu en and ol age, wi e eed speed
(WFS), a el speed (TS) and gas low a e. Below is an example o knowledge-based
ules used in Figu e 3:
I ma e ial = aluminium (speci ica ion: 4,043 A),
and i geome y complexi y = s aigh wall,
and i wall wid h = 5 mm,
hen p ocess cu en = 75 A, p ocess ol age = 12.5 V, WFS = 4 m/min, TS = 0.4 m/min,
gas low a e = 16 L/min.
3.6 Cos model alida ion and implemen a ion
The cos model has been alida ed concep ually on he cos es ima ion me hodology,
cos b eakdown s uc u e (CBS), cos es ima ing ela ionships (CERs) and cos es ima-
ion p ocess by h ee expe ienced expe s:
Expe 1: A p ojec manage o addi i e manu ac u ing p ojec wi h mo e han
h ee yea s o ield expe ience has been used o alida e he emanu ac u ing
p ocess model and p ocess da a.
Expe 2: A cos enginee ing expe wi h o e 10 yea s o expe ience in cos
es ima ing has been used o alida e he cos es ima ion me hodology and he CBS.
Expe 3: Ano he cos enginee ing expe wi h o e 4 yea s o expe ience in cos
es ima ing has been used o alida e he cos es ima ion me hodology.
In addi ion, he da a collec ed in he cos es ima ion model also has been ini ially ali-
da ed. The alida ion has con i med ha he da a used in he cos model a e wi hin he
Figu e 3 Rela ionship be ween inpu pa ame e s and p ocess pa ame e s.
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easonable anges; he cos model is de eloped logically and i is alid o mee he pu pose
o e alua ing he economic bene i o emanu ac u ing based on speci ic echniques. The
imp o emen s made o he cos es ima ion model h ough he alida ion a e as ollows:
In he emanu ac u ing p ocess modelling, wo scena ios o deposi ing equipmen a e
conside ed in he deposi ing cos es ima ion. One is a obo a m assembled in a
deposi ing machine, while he o he one is a gan y combined wi h a deposi ing machine.
Ope a o s can choose a sui able se up o hei needs in emanu ac u ing applica ion.
In he cos modelling, de ini ion o an inpu pa ame e , geome y complexi y, is
e ised o cla i y so ha he model use s can inpu alue co ec ly o hei cases.
The cos model de eloped has been implemen ed in MS Excel® pla o m. Rela ed de-
posi ing and g inding speci ica ions a e embedded in o he sp eadshee . Figu e 4 shows
he model in e ace including inpu pa ame e s and no malised ou pu s.
4 Case s udy
4.1 Remanu ac u ing o sla ack
An end-o -li e sla ack has been selec ed o demons a e he applica ion o he de el-
oped cos model, i.e. o e alua e i his sla ack is economically iable o emanu ac-
u e in compa ison wi h making a new one. Sla ack is a componen linked o sla s in
ai c a wing, i conduc s he mo ion ails o he sla s. The sla ack used in his s udy
(as shown in Figu e 5) is designed by Thomas Fal ey in his MSc hesis a C an ield
Inpu s Ou pu
Value Uni
No malised
Cos Uni
Pa Volume 10000 mm3 Va iable Cos 24.11
Wall Wid h 3 mm Se up Cos 12
Ma e ial Type i al/ i/s Deposi ing Cos 11.28
Complexi y 1 (1-5) G inding Cos 0.83
Pa Quan i y 1 One-o Cos 32.56
Da a P ocessing Cos 10
Tes Run Cos 22.56
To al Cos 56.67
Figu e 4 In e ace o MS Excel
W
based cos model.
Figu e 5 CAD model o he sla ack.
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