Interntion Journ of Opertion Reerch Interntion Journ of Opertion Reerch Vo. 9, No. 2, 76 86 (2012) Green Vendor Seection with Rik Anyi Hio-Fn Wng nd Wei-Ling Ko Deprtment of Indutri Engineering nd Engineering Mngement, Ntion Ting Hu Univerity, Hinchu, Tiwn Received November 2011; Revied Mrch 2012; Accepted Mrch 2012 Abtrct Becue the concioune of environment protection, mny iue reted to Green Suppy Chin (GSC) re dicued. Different from trdition uppy chin, GSC re concerned bout environment impct nd mteri utiiztion iue, which mke the eection of the uppier more compicted. The mindet of prevention prior to cure nd the retriction of the Europen Union render green mteri nd component critic iue from the beginning of production. According to the regution of the EU nd iue of uppier eection criteri, uppier eection i type of muti-criteri probem. Thu, thi reerch ue AHP nd FMEA to contruct hierrchy tructure for thi purpoe. By conidering the minim rik nd cot, compete nyi i conducted. Deciion mker cn foow rue to cibrte the reut of deciion nd etbih benchmrk to identify uitbe uppier; in the mentime to improve the ince retion by the enitivity nyi propoed in thi tudy. Keyword AHP, green vendor rnking & eection, rik mp, ince deveopment 1. INTRODUCTION Trdition uppy chin mngement fce riing environment concioune in recent decde, nd the procee of trdition uppy chin mngement reuire re-exmintion under conidertion of green fctor. There re vriou directive nd regution tiputed for green product, uch WEEE (2003), RoHS (http://www.roh.gov.uk, 2010), EuP (http://www.eup-network.de, 2010), etc. In the pt, the uppy chin mngement focued on informtion fow, which owed the chin to work effectivey nd efficienty; where, contemporry uppy chin mut o fufi green fctor regution. Purching i one of the mot critic tge in green uppy chin. In green uppy chin, hzrdou nd hrmfu ubtnce wi ccumute throughout the procee, nd purching ctivitie of green uppy chin eek green uppier to provide cening mteri nd component in order tht the end-product coud conform to green regution. Thi pper propoe method of rik etimtion nd eection for green uppier guidnce for the mnufcture o tht mnufcture i not ony be to eect the uified vendor; but o to improve the green uity of the vendor. The pper i orgnized foow. Literture of uppier eection nd green uppier criteri re urveyed in Sec. 2. The methodoogy of thi pper i propoed in Sec. 3, with the enitivity nyi nd it ppiction to the ince deveopment. The t ection i the concuion of thi tudy. 2. LITERATURE REVIEW Suppier eection i n iue under ong-term dicuion nd deveopment. Recenty, Ho et., (2010) reported review of uppier evution nd eection, indicted tht the mot popur evuting criteri re uity, deivery, nd price/cot. From the criteri of vendor eection, it cn eiy be reized tht the eection of different uppier i typic muti-criteri deciion mking probem. Anytic Hierrchy Proce (AHP) i mutipe criteri deciion-mking too ued in mny ppiction reted to deciion-mking (Stty, 1980; Vidy et., 2006). AHP often ppie to muti-criteri deciion probem, but it i freuenty the ce tht the DM i certin bout the rnk order of the criteri but uncertin bout the precie numeric weight (Wng, 2004). However, Hurey (2001) h propoed method to vry the weight by giving ech eement n exponenti prmeter in the pirwie mtrix. The reutnt rnge of prmeter α cn give the DM ome fexibiity on the weight. Ao, ome reercher uch Chn et. (2007) hve ppied Fuzzy pproch to coping with uch uncertinty. Fiure Mode nd Effect Anyi (FMEA) firt emerged from tudie by NASA in 1963. It empoy Rik Priority Number (RPN) to meure the rik nd everity of fiure. RPN conit of three indictor, nmey, Occurrence (O), Severity (S), nd Detection (D). Thi biity mke it pproprite to ue FMEA to e the rik ocited with green component (Hu, et., 2009). Utiity function i device tht untifie the ttitude of DM towrd rik by igning Correponding uthor emi: hiofnwng@gmi.com 1813-713X Copyright 2012 ORSTW
77 numeric index for indifference eve of comprion for criterion. Genery, deciion mker re cified into three type, nmey, rik verion, neutr rik nd rik prone, nd the DM rik ttitude i refected in the hpe of the utiity curve (Kinum et., 2006). Bed on the pt uppier eection criteri (Webber, 1991; Ho et., 2010) nd the dicuion with numerou expert, thi pper wi conider ddition green criteri which rete to EU regution to evute green uppier. Since AHP h been widey uing in uppier eection probem to provide objective weight of criteri (Ho et., 2008), in the pper, we h dopt it our min frme of nyi. On the viewpoint of rik evution, FMEA wi be integrted into the frmework to repreent the objective pect of the rik meure; where the utiity theory i dopted to meure DM ubjective eve towrd the rik. Finy, the enitivity nyi of the exponenti prmeter in AHP nd the prmeter in utiity function wi provide DM ome informtion of the critic fctor in mngement; we the guideine of improvement of prtnerhip with uppier. The whoe procedure wi be introduced in next ection. 3. RISK ANALYSIS OF VENDOR SELECTION Thi ection decribe the frmework of green uppier eection nd the deti of the evution method. 3.1 Contruction of Hierrchic Structure When evuting uppier green rik, there re four mjor criteri for meurement. The green improvement of thi evution tructure i the conidertion of environment impct nd Life-Cyce Anyi (LCA), which re different from the trdition evution criteri. The firt criterion i Income Quity Contro (IQC), uing the nottion to repreent. The content of environmenty enitive ubtnce re controed or forbidden, thu, thi tudy im t IQC, of green uppier, in order to ditinguih whether uppier conform with RoHS. Secondy, the Diemby Effort Index (DEI) i criterion tht meure the effect of product ifecyce, uing the nottion d to repreent. DEI hep u to know the infuence of the mteri/component in the future, by enuring tht the mteri/component re recycbe. The third criterion i the performnce of vendor mngement nd repreent by the nottion vm. Thi criterion cn evute the performnce of mngement in 5 dimenion. The firt dimenion i ef-inpection report, where ech uppier i compeed to initite bic improvement in mngement performnce. The econd dimenion i ctu inpection report, where the objective point of view of expert peciizing in inpection provide ccurte reut. The third dimenion i wrrnty, where uppier mke commitment, by vouching for their mteri/component content conformed to w. Moreover, the fourth nd fifth dimenion re certifiction tht come from interntion certifiction orgniztion or we-known enterprie. Through uch meure, uthorittive orgniztion certify, proof of conformity, tht the nmed uppier hve good mngement performnce. The fourth criterion i ogitic eve, where uppier work coopertivey with prtner in uppy chin, the reut of which re increed efficiency nd profit for member. Thi criterion ue the nottion to repreent. The bove mentioned criteri retionhip cn be drwn hierrchic tructure, hown in Figure 1. The meurement method of ech criterion i dicued in the next ection. Green Suppier Grde DEI, d IQC, Logitic, Vendor Mngement, vm Actu Inpect Report Sef-Inpect Report Admit of Powerfu Enterprie Wrrnty Certifiction Time Too Fixture Intruct Hzrd Force Severity Detection Freuency Acce Recovery Rte Figure 1. Hierrchic nyi tructure of green uppier eection
78 3.2 Evution of the Weight of the Criteri In order to meure the weight of importnce of different criteri, in thi ection two different evution method from different pect re propoed beow: 3.2.1 Subjective Evution Rik Utiity Function Since the concioune of the rik i different from ech one, utiity function i dopted by rticuting DM rik ttitude. Firt of, thi ytem wi etbih the bet nd wort core of ech criterion, then the bet core utiity vue i U = 1, nd the wort core utiity vue i U = 0. After deciding the bet nd wort core, the mid-core C between thee two core i computed. According to the probbiity we cn compute the expect vue of mid-core C utiity vue, U. c When three point i obtined for the utiity function, the utiity function cn be computed. The exponent prmeter of ech criterion wi how the rik ttitude of the DM. The utiity function i hown Eution (1): v v f () x x v {, d, vm,} v (1) 3.2.2 Objective Evution AHP Whie the utiity function how the ubjective meure of DM rik ttitude towrd ech ttribute, to the objective meure of the weight of ech criterion, wi be etimted by conducting AHP with euenti ggregtion of pirwie evution of criteri in ech hierrchy. The evution reut 9 eve ce, which i recommended by Sty (1980). Let A be the pirwie mtrix, bed on Eution (2), ech pirwie mtrix eigenvue i computed to obtin the eigenvector the weight of criteri: Aw mx w (2) where i the rget eigenvue. Athough pirwie comprion i vid method for obtining weight, mx inconitencie houd be conidered. In ddition, to void the uncertinty when DM perform the pirwie compriion, in thi tudy we dopt Hurey method (Hurey, 2001) to vry the weight by giving ech eement of pirwie mtrix n exponenti prmeter foow but preerve the rnked order of the ttribute in mtrix, which not ony reut in confidence for the AHP recommendtion, but o provide the DM ome fexibiity in djuting the weight: = 1: it repreent the origin mtrix nd wi not ffect the conitency rtio of the pirwie mtrix. > 1: the order of weight wi be the me the origin, but the rget weight wi incree whie the other weight decree, nd the conitency rtio wi incree 0 < < 1: the order of weight wi not chnge, but the rget weight wi decree whie the other weight wi incree, nd the conitency rtio wi decree. = 0: the eement in the comprion pirwie mtrix re eu to 1, thu, the weight remin the me. The mtrix become the mot conitent mtrix, o the conitency rtio i 0. 3.3 Meure of Criteri Thi ection introduce the method for untifiction, incuding the four mjor criteri: IQC, DEI, vendor mngement, nd ogitic. 3.3.1 Income Quity Contro (IQC, ) To enure the mteri/component conform with RoHS, thi criterion i ued to evute the rik of hzrdou ubtnce be on the feedtock inpection report. () Severity, S : S define the probbiity tht the content of hzrdou mteri wi not p the reuired eve. It cn ue the reuet of RoHS the upper bound of normiztion. The ower bound i dependent on the technic deveopment.
79 Therefore, by Eution (3), the dt of inpection report cn be normized into vue between 0 nd 1: x ijk Inpected Vue - LB, UB LB i {1 ~ n}, j {1, 2, 3}, k {1 ~ 6} (3) where, i i the number of inpection report, j indicte rik eve, nd k i kind of hzrdou mteri indicted in Tbe 1. Ech hzrdou mteri wi ony beong to one type of rik eve of high ( H ~ ), medium ( M ~ ) nd ow ( L ~ ). Tbe 1. Hzrdou mteri k = 1 2 3 4 5 6 Hg Cd Pb Cr(VI) PBB PBDE Becue reut re ccording to the experience of inpector, ech rik eve i repreented by fuzzy number, define by Eution (4). On the premie tht the ctegoriztion reibiity i, the fuzzy number L ~, M ~, nd H ~ wi become the crip et L, M, nd H. Integrte ech prt of component rik etimtion to denote the everity of the component, which my not p EU detection, hown in Eution (5). 1, 0 x 0.25 ( x) 4(0.5 x), 0.25 x 0.5 L 0, x 0.5 0, x 0.25 4( x 0.25) 0.25 x 0.5 ( x) M 4(0.75 x) 0.5 x 0.75 0, x 0.75 0, x 0.5 ( x) 4( x 0.5), 0.5 x 0.75 H 1, x 0.75 (4) S n n n L x M x H x i1k i2k i3k i 1 k 1 i 1 k 2 i1 k3 (5) L M H n L M H n L M H n (b) Freuency, F : The tot number of fied inpection report re recorded in S. Freuency F refer to the rtio of tot inpection report to fied inpection report. When fied report pper in the inpection proce, it men the uppier product contin ome type of rik C. Then the fied inpection report rtio cnnot over rtio C which i etbihed by the DM. If fied report pper, hown in Eution (6). F wi increing from C. C pu C wi become 1. The ccution method i F 0 x C n M if x 0 x if 0 C (6) n otherwie where, n denote the tot number of inpection report, nd x denote the number of fied inpection report. M repreent rge poitive number. If the fied inpection report rtio over C, then the uppier wi not be conidered t.
80 (c) Detection, D : The eve of difficuty in detection i dependent on the rtio of the degree of diemby to pure mteri. Upon inpection of n entire component, the concentrtion of hzrdou mteri woud be diuted, nd thu, decree the ccurcy of the inpection. Thi pper ue mixed rtio to denote the rik of detection. D i re number which repreented by the mix rtio of inpection. After obtining the three dimenion of rik etimte, ccording to the weight ggregte, it become the IQC rik etimte. Ech dimenion weight obtined from AHP, which the index denoted different dimenion of weight. The rik etimte of IQC cn be obtined through foowing Eution (7). Rik w S w F w D IQC S F D (7) 3.3.2 Diemby Effort Index The ide green uppy chin i coed-oop. A component/mteri cn be reued, remnufctured, or recyced, nd wi not produce ny wte. Therefore, t the beginning tge, preconception of the other tge itution reuire pre-ction, uing the Diemby Effort Index (DEI) core crd (Kuo, 2006) to nye the uppier component/mteri effect during the diemby tge.the DEI crd i hown in Figure 2. Ech criterion core rnge between 0 nd 25, the mer the better. Ech core i then normized into unit interv between 0 nd 1 in order to expre the rik etimtion. 1. TIME (Sec) >210 140 90 50 25 <5 2. TOOLS Improvied Speci OEM Mechnic Air Gun None 3. FIXTURE Automtion Winch Cmp Two-Hnd One-Hnd None 4. ACCESS Not Viibe Du-xi From beow >6" deep X/Y-xi Z-xi 5. INSTRUCT 6. HAZARD 7. FORCE -Unften -Humn -Mchine Trining Contct OEM Group Dicu >30 ec 10-2- ec None Body-uit Air Suppy Fire Protection Fce Mk/ Arm wrp Gove High >50 b >300b Low-impct 35 220 Leverge 24 160 Orthogon 15 110 Torion 7 75 None Axi 2 50 8. RECOVERY RATE <50% 55% 65% 75% 85% >90% Figure 2. DEI core crd (Kuo, 2006) After obtining criteri rik etimtion, nd ccording to ech weighted ggregte to become the DEI rik etimtion. Ech criterion weight i computed by AHP, which the index denoted different criterion of weight. Rik, {,,,,,,, } DEI w y DEI DT TO FI A I H FO R i i (8) idei
81 3.3.3 Vendor Mngement According to the prctice of AVECTEC (2009), the criteri of vendor mngement incude two mjor evution item nd three bonu item. The two mjor evuted reource re ef-inpection report nd ctu-inpection report. There re 12 min item in the inpection report, nd ech min item h different number of ub-item. 3.3.3.1 Rue of Report Evution () Recording Method: There re four eve of core to evute ech ub-item: 0 denote toty untified, 1 denote edom tifie, 3 denote prty tified, nd 9 denote toty tified. When the ub-item core i ower thn, or eu to 1, then the ub-item i recorded 1 for fiure (AVECTEC, 2009). 1, if item 1 ij f ( item ) r ij 0, if item 3 ij i {1 ~ 12} (9) Tbe 2. Amount of ub-item in min item (AVECTEC, 2009) i = 1 2 3 4 5 6 7 8 9 10 11 12 j = 19 9 9 21 12 24 76 15 14 6 8 8 (b) Evution Method: Ech min item ue the verge core of the ub-item for performnce expreion: item f ( item ) i ij j item # j ij i {1 ~ 12} (10) (c) Stndrd for P: When the verge core of the min item i over 7 commony dopted, then the uppier pe the inpection tndrd. If uppier verge core i ower thn 7, it men the uppier mngement performnce h not yet reched the reueted eve. Then the performnce of vendor mngement wi how rge number M for expreion. 3.3.3.2 Inpection Report Since there re two type of inpection report: ef- inpection report, nd the ctu inpection report. They re denoted nd repectivey. () Severity, S nd S : When the core of n inpection report i high, the vendor mngement h the greter performnce. When uppier h good performnce in mngement, then the component/mteri reibiity wi o be high. A 1 denote the wort ce in rik evution, thi tudy ue 1 minu verge core of the min item in order to repreent the everity, hown in Eution (11). S 1 i item 129 i {, } (11) (b) Freuency, F nd F nd F : F ue the rtio of the tot number of ub-item to fiure item in order to expre freuency. The everity S nd computtion method i hown in Eution (12). S repreent the rik of degree, nd freuency F nd F repreent the rik of occurrence. The
82 F 12 i1 j f ( item ) r j ij {, } (12) (c) Detection, D nd D : Thi rting i ccording to n uditor ubjective opinion, nd cn reut in three eve rting inpection proce, nd the rting i in inguitic form, thi tudy ue three fuzzy number, nmey, E, N, nd H in order to expre, which re imir to Eution (7). On the premie tht the uditor reibiity i, then, the fuzzy number E, N, nd H wi become the crip et, E, N nd H. After obtining the three dimenion of rik etimtion, due to tht ech weight ggregte my become efinpection or n ctu inpection rik etimtion, ech dimenion weight i obtined from AHP, nd the index denoted different dimenion of weight. A thee two evution item form re the me, the ony difference i the uditor opinion. Thu, the weight of S nd S re denoted by w repectivey. Simiry, S i w nd F i w denote the weight D i of the repective freuency nd detection. The rik etimtion of ef- inpection nd ctu inpection cn be obtined by foowing Eution (13) nd (14). Rik w S w F w D ef inpect S F D i i i Rik w S w F w D ctu inpect S F D i i i (13) (14) 3.3.3.3 Recognition nd Certifiction The wrrnty decrtion of powerfu enterprie nd certifiction re item of exception for vendor mngement, the wrrnty i bic gurntee of uppier product. Stndrdized certifiction of thoe interntion orgniztion tht ue ISO incude the two binry vribe, P nd C, in order to expre the c of wrrnty nd certifiction. The other item of exception i the decrtion of powerfu enterprie, by dmitting to product with different tndrd nd effect, thi wi enbe peci cifiction for thee enterprie. There re three eve of cifiction, nmey,,, nd. c i the mot fmou nd powerfu interntion enterprie, foowed by c, etc. Y i poitive integer i which expree the number of decrtion from different eve of enterprie. After obtining rik etimtion of both ef nd ctu inpection report, nd ny item of exception dt, the next tep i the ggregtion by the repective weight which re obtined from AHP. Rik MAX{ w Rik w Rik mngement A ctu inpect S ef inpect ( w Pw CwY wy wy ), 0} Y PC, {0,1} i {,, } i P C (15) Note tht whie rik etimtion i computed, the rnge of rik vue i between 0 nd 1. Therefore, we tke the mximum between the computed reut nd 0, nd thu, obtin reonbe vue. 3.3.4 Logitic () Severity, S : S meure the time period, x, of the number of week go the uppier w out of tock in the pt two yer. t The unit between the two time point i one week nd thu 104 week in tot of two yer. An power function, f( x ) wi expre the everity of the time period time period by the DM. x. Becue the time period t xt i the rger the better, o uing tot week minu x expre the rik of out of tock. Prmeter repreent the infuence of out of tock, which i decided t t
83 104 xt S f( x ) ( ) 0 x 104 t 104 t 0 1 (16) (b) Freuency, F : Thi repreent the number of order, Eution (6). The ide i the imir with F. x N, tht hve been out of tock mong the tot order N, hown in (c) Detection, D : Becue S nd F ue the record of trnction to evute uppier ogitic eve, n uditor wi, ccording to their ement, provide inguitic ttement to decribe the trnction record ttu. There re three eve of ttu: Cer C, Norm N, nd Uncer U which re imir to Eution (4). On the premie tht the uditor reibiity i, the fuzzy number C, N, nd U wi become crip et C, N, nd U. After obtining the three dimenion of rik etimtion, nd ccording to ech weight to ggregte, to become the ogitic rik etimtion. Ech dimenion weight obtined from AHP, which the index denoted different dimenion of weight. The rik etimte of ogitic cn be obtined by foowing Eution (17). Rik w S w F w D ogitic S F D (17) 3.4 Suppier Evution nd Seection The rik ggregtion method nd uppier rnking method re introduced, foow. 3.4.1 Rik Aggregtion Method Prior to untifiction, the ccuted utiity function of the four mjor criteri re bed on the rik ttitude of the DM, nd re obtined through the untifiction proce, in order to determine ech criterion rik etimtion. Ech dimenion rik etimtion wi trnfer to the rik utiity vue, by the utiity function. However, the rik etimtion hve different pttern of inge vue nd crip et. The trnformtion method i hown in Eution (18). f ( x) if UB LB v UB f ( x) v f ( x) dx if UB LB v ( UB LB) 1 LB (18) The fin tep i integrting the rik utiity vue with objective weight. There re four min criteri in uppier eection, nmey, IQC, DEI, vendor mngement, nd ogitic. Ech criteri weight obtined from AHP, which the index denoted different criteri of weight. For exmpe w denote the weight of the IQC, etc. The integrted function i determined hown in Eution (19). R f ( Rik ) w f ( Rik ) w f ( Rik ) w f ( Rik ) w (19) IQC d DEI d vm mngement vm ogitic 3.4.2 Rnking Method Ech uppier wi hve rik etimtion R nd cot. The uppier rik mp ue thi informtion two coordinte vue, of which ech h it threhod the minimum owed vue, nd the rik of vioting n green egition i conidered more eriou thn cot in vendor evution. One threhod i the expected cot of the DM, the other i the expected rik eve of the DM. Therefore, there re four ctegorie of uppier, nmey, A, B, C nd D hown in Figure 3. Ctegory A i the firt priority becue their rik etimtion nd cot re ower thn the expecttion of the DM. Ctegory B i the econd priority. Athough the cot i high, if the enterprie h ny record of viotion green egition, the dmge i much more eriou. If the cot to the compny reputtion i not too high, DM wi conider the uppier in
84 ctegory C, which cn offer ow cot, but hve high rik component/mteri, nd thu, reuire guidnce nd itnce to cro the threhod. Rik Etimte C D A B 0 Figure 3. Rik mp of the uppier Cot The uppier which i cified in Ctegory D men it h both high rik nd cot, nd woud be the t choice for uppier eection. The DM my djut the deciion proce to ow the uppier eve chnging. How to djut eve with the et chnge nd how to provide guidnce nd itnce re dicued in the next ection. 3.5 Senitivity Anyi nd Aince Deveopment Becue it i importnt for n enterprie to deveop good ince retion ong the uppy chin, therefore, the purpoe of enitivity nyi in thi tudy re focued on the identifiction of critic fctor; nd o to etbih guideine for improving the uppier in order to conform to the reuirement of mnufcturer. In thi tudy, there re two chnne for DM to preent the preference: AHP nd the utiity theory. Thee two method re independent of ech other with repect to the objective nd ubjective judgement. After ccuting uppier rik etimtion, enitivity nyi cn be empoyed to find the critic fctor of rik meure for deveoping guidnce for uppier in Ctegory C to cro the threhod. In the other hnd, critic fctor in cot cn be identified for upporting the uppier in Ctegory B on getting better green performnce, nd increed competitivene. Therefore, enitivity nyi i performed by hoding two condition of (1) retining uppier ctegory when the prmeter hve vried; nd (2) retining the order of uppier rik etimte when prmeter hve vried. In coneuence, the outcome of the enitivity nyi determine the owbe rnge of prmeter v of the utiity function, of which the mer the owbe rnge, the greter i the degree of enitivity. Ao, by ppying Hurey method (2001) of igning ech eement in the min criteri comprion pirwie mtrix with n exponent prmeter tted in Section 3.2.2, the enitivity of the prmeter in AHP cn be evuted. 3.6 Summry nd Dicuion The rik etimtion of green uppier cn be computed by foowing the procedure. Bed on different DM, the preference nd the rik ttitude of ech criterion wi ed to different rik etimtion. In ummry, the rik etimtion of green uppier cn be computed by foowing the procedure. Step1: Contruct hierrchy tructure be on the retion of the conidered criteri. Step2: Derive the ubjective rik etimte by Utiity Function of the min criteri nd meure the weight of Criteri by AHP by Sec. 3.2. Step3: Quntify the rik eve of ech ub-criterion by foowing the procedure of Section 3.3. Step4: Aggregte the rik etimtion by Eution (19) to obtin the over rik eve. Step5: Given the threhod of the owed rik nd cot to etbih rik mp; then pot the rik core of ech uppier on the mp for rnking. Step6: Through enitivity nyi to find the mot enitive prmeter nd etbih ince trtegy. Different deciion mker woud hve different preference nd the rik ttitude of ech criterion which wi ed to different rik etimtion. According to enitivity nyi, the DM coud undertnd the owed vrition nd o the key fctor for mngement. The propoed method h been ppied to the ce of eecting bckight uppier tht conform to EU regution nd directive by TFT-LCD Origin Euipment Mnufcturer (OEM). Two uppier hve firt undergone 5 tep; nd
85 Suppier 1 which fe in the Ctegory A with e rik eve nd cot h been eected. Athough Suppier 2 with higher rik w not in fvour, in order to mintin the prtnerhip ong the uppy chin, it i the DM of thi OEM who i reponibe to upervie Suppier 2 o tht Suppier 2 rik eve cn be reduced. Coneuenty, enitivity nyi to identify the ignificnt fctor in rik w conducted for uch ince mngement. The reut h hown tht, IQC i the mot critic fctor nd houd be improved to effectivey reduce the rik eve. Furthermore, mong the fctor of IQC, the outcome from the enitivity nyi uggeted tht if Suppier 2 wnt to dvnce to higher c, the firt improvement houd be tken to decree the number of fied inpect report. Tht i, they hve to check the content of hzrdou ubtnce, which incude the improvement of their technoogy of production nd their mnufcturing uity eve. Secondy, it i to incree the ccurcy of inpect report by diembing the component o tht purer mteri cn be preented for inpection. 4 CONCLUSION Thi pper propoe n evution procedure to upport the deciion of green uppier eection. Different from trdition uppier eection, the criteri of green uppier eection mut conider word-wide regution for environment protection. Bed on thee green criteri, thi thei contruct hierrchy tructure to conduct compete nyi of green uppier. Through rik nyi of green uppier, ech uppier wi be cified ccording to their rik etimtion nd the cot, trcked on uppier rik mp. The uppier rik mp provide the reuired reference for the DM to mke deciion. In ummry, the improvement of thi pper over other iterture re foow: 1. By engging in dicuion with numerou expert in reted fied, the green criteri of thi tudy, competey conider the regution of the EU, uch RoHS, WEEE nd EuP, nd re uitbe for intnt ppiction. 2. Integrting FMEA with AHP render rik evution more ytemtic, nd the integrtion of the utiity theory refect the rik ttitude of DM more honety. 3. Thi pper provide method of rik untifiction for ech green criterion by uing fuzzy number to expre ome inguitic informtion. 4. The uppier rik mp provide intinctive informtion, which cn hep the DM to comprehend the interretion between ech uppier. 5. The cheme of enitivity nyi provide the DM to conform the eected vendor nd bove to improve the ince retion with the cndidte uppier. Future work tht cn be extended from thi tudy i uggeted to ppy the rik etimtion nd cot input prmeter of mthemtic progrmming mode uch tht the purche untity of ech uppier cn be ccuted (Kokngu et., 2009). ACKNOWLEDGMENT Thi tudy i prtiy upported by Ntion Science Counci, Tiwn, ROC with project no. NSC 97-2221-E007-095-MY3; nd prtiy by AVECTEC with project no. 97A0313JB. REFERENCES 1. AVECTEC (2009). Methodoogy nd Prototype Deveopment for Green RoHS Rik Contro Modue, Technic Report. 2. Chn, F.T.S. nd Kumr, N. (2007). Gob uppier deveopment conidering rik fctor uing fuzzy extended AHP-bed pproch. Omeg, 35: 417-431. 3. De Boer, L., Lbro, E. nd Morcchi, P. (2001). A review of method upporting uppier eection. Europen Journ of Purching & Suppy Mngement, 7: 75-89. 4. Dickon, G.W. (1996). Anyi of vendor eection ytem nd deciion. Journ of Purching, 2(1): 5-17. 5. Ho, W. (2008). Integrted nytic hierrchy proce nd it ppiction A iterture review. Europen Journ of Opertion Reerch, 186: 211-228. 6. Ho, W., Xu, X. nd Dey, P.K. (2010). Muti-criteri deciion mking pproche for uppier evution nd eection: A iterture review. Europen Journ of Opertion Reerch, 202: 16-24. 7. Hu, A.H., Hu, C.-W., Kuo, T.-C. nd Wu, W.-C. (2009). Rik evution of green component to hzrdou ubtnce uing FMEA nd FAHP. Expert Sytem with Appiction, 36: 7142-7147. 8. Hurey, W.J. (2001). The nytic hierrchy proce: A note on n pproch to enitivity which preerve rnk order. Computer & Opertion Reerch, 28: 185-188. 9. Kinum, Y. nd Twr, N. (2006) A mutipe ttribute utiity theory pproch to en nd green uppy chin mngement. Intern Journ of Production Economic, 101: 99-108. 10. Kokngu, A. nd Suuz, Z. (2009) Integrted nytic hierrch proce nd mthemtic progrmming to uppier eection probem with untity dicount. Appied Mthemtic Modeing, 33: 1417-1429.
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