Develop a cost model to evaluate the economic benefit of remanufacturing based on specific technique

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 S anda d-Nu zungsbedingungen: Die Dokumen e au EconS o dü en zu eigenen wissenscha lichen Zwecken und zum P i a geb auch gespeiche und kopie we den. Sie dü en die Dokumen e nich ü ö en liche ode komme zielle Zwecke e iel äl igen, ö en lich auss ellen, ö en lich zugänglich machen, e eiben ode ande wei ig nu zen. 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I he documen s ha e been made a ailable unde an Open Con en Licence (especially C ea i e Commons Licences), you may exe cise u he usage igh s as speci ied in he indica ed licence. h p://c ea i ecommons.o g/licenses/by/2.0/ 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. Xu and Feng Jou nal o Remanu ac u ing 2014 2014, 4:4 h p://www.jou nalo emanu ac u ing.com/con en /4/1/4 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. Xu and Feng Jou nal o Remanu ac u ing Page 2 o 12 2014, 4:4 h p://www.jou nalo emanu ac u ing.com/con en /4/1/4 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. Xu and Feng Jou nal o Remanu ac u ing Page 3 o 12 2014, 4:4 h p://www.jou nalo emanu ac u ing.com/con en /4/1/4 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 Xu and Feng Jou nal o Remanu ac u ing Page 4 o 12 2014, 4:4 h p://www.jou nalo emanu ac u ing.com/con en /4/1/4 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. Xu and Feng Jou nal o Remanu ac u ing Page 5 o 12 2014, 4:4 h p://www.jou nalo emanu ac u ing.com/con en /4/1/4 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 Xu and Feng Jou nal o Remanu ac u ing Page 6 o 12 2014, 4:4 h p://www.jou nalo emanu ac u ing.com/con en /4/1/4 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. Xu and Feng Jou nal o Remanu ac u ing Page 7 o 12 2014, 4:4 h p://www.jou nalo emanu ac u ing.com/con en /4/1/4 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. Xu and Feng Jou nal o Remanu ac u ing Page 8 o 12 2014, 4:4 h p://www.jou nalo emanu ac u ing.com/con en /4/1/4