The design and management of logistics services markets

Transcription

1 The desgn and management of logstcs servces markets 19 th Internatonal Conference on Producton Research V. Albno, R.M. Dangelco, A. Messen Petruzzell DIMeG, Poltecnco d Bar, Vale Japga 182, Bar, Italy Abstract Supply chan management has become more and more dffcult because of the ncreasng complexty and expanson of supply chans (SCs). In ths context, collaboraton and coordnaton of logstcs flows among SCs actors, such as supplers, customers, and logstcs provders, play an mportant role to enhance SC performance n terms of tme and. In ths paper, the desgn and management of logstcs servces markets through the coordnaton and the collaboraton among the actors of a supply stage s analysed. In partcular, three coordnaton polces based on vehcle consoldaton and on dfferent levels of collaboraton among the actors are dentfed and evaluated n terms of transportaton, coordnaton, and servce lateness s. Fnally, the coordnaton polces and the collaboratve relatonshps among the actors operatng n the Italan dstrbuton network of two automotve companes are analysed as a case study. Keywords: coordnaton; collaboraton; logstcs servces markets 1 INTRODUCTION In the current economc scenaro, few products for sale n any country are entrely produced by domestc frms makng use of domestc nputs only. It has become the rule rather than the excepton that products, components of products, or resources used n the producton of products are of foregn orgn. Then, n order to be customers responsve and s effectve, logstcs s becomng more mportant for frms. Due to the hgh degree of specalzaton characterzng nowadays logstcs, such actvtes are generally outsourced to specfc actors who make these servces ther own corebusness. These actors, known as thrd-party logstcs (3PL) provders or logstc servce provders (LSPs) [1-2], permt the nterconnectedness among the dfferent actors of the supply chan, world-wde located. 3PL provders try to satsfy the needs of dfferent actors both upstream and downstream n the supply chan, wth greater effectveness and effcency than compettors. In ths context, servce effectveness represents the extent to whch customers requrements are met, whle servce effcency represents the measure of economcal resources used to acheve a certan level of customer satsfacton [3]. In the lterature, dfferent types of logstcs servces carred out by 3PL provders have been dentfed [4-6]. Among the dfferent types of logstcs servces, transportaton s one of the most mportant for supply chans effcency and effectveness, as emprcal researches conducted by scholars and practtoners demonstrated. In fact, these studes show that transportaton s the most frequently logstcs servce requested by frms; about more than 50% of the frms utlze logstcs provders for transportng goods [7-8]. The mportance of transportaton for the actual compettve scenaro s also hghlghted by the effort spent to desgn and manage effectve and effcent transportaton networks, such as pont-to-pont, corrdor, and hub-and-spoke systems [9-11]. An effectve desgn of transportaton systems nvolves also problems related to vehcle schedulng, vehcle routng, and lateral transhpments [12-15]. Great attenton has been pad n lterature to the mportant role played by coordnaton as a mechansm by whch mprovng supply chan performance [13-16]. The concept of coordnaton has been thoroughly studed by several poneer researchers [17-20]. A coordnaton mechansm conssts of the nformatonal structure, defnng who obtans what nformaton and how uses that nformaton, and of the decson-makng process, whch helps to select the approprate acton from a set of alternatve solutons [21]. Logstcs represents a typcal actvty whose coordnaton s partcularly mportant for the compettve advantage of supply chans and networks, especally when actors are vertcally dsaggregated (ndependent unts) and located n dfferent places. A way n whch logstcs flows coordnaton can be acheved s by means of consoldaton [22], whch s the process of combnng dfferent tems, produced and used at dfferent locatons (spatal consoldaton) and/or at dfferent tmes (temporal consoldaton), nto sngle vehcle load [23]. Two types of spatal consoldaton, namely vehcle and termnal, and one type of temporal one, namely nventory consoldaton can be dentfed. Consoldaton strateges can be analysed takng nto account two dfferent dmensons: quantty and tme [24]. Then, accordng to these dmensons t s possble to make dstncton among the followng consoldaton polces: ) a tme polcy; ) a quantty polcy; ) a tmequantty polcy. Consoldaton strateges depend also on the transportaton models adopted, as shown by Hall [25] who examnes the nterdependence between freght mode and shpment sze when they are chosen smultaneously to mnmze transportaton and nventory s. The adopton of consoldaton strateges determnes relevant benefts for the whole system, n terms of reducton of nventory holdng tme, ncreasng load factors, and reducton of varablty of transportaton means. However, some drawbacks rse, n partcular for customer servce. Then, trade-offs have to be consdered between system logstcs performance and customer servce level [26]. The am of the paper s to analyse the role of coordnaton polces n order to desgn and manage an organzed logstcs servces market. In partcular, coordnaton s related to the vehcle consoldaton of products n the transportaton servce market for a supply stage. To cope wth ths am, a model for evaluatng the benefts (n terms of reducton of transportaton s) and the s (n terms of ncreasng of coordnaton and servce

2 lateness s) arsng from consoldaton, n dfferent collaboratve contexts, s developed. The paper s structured as follows. In the next secton an analyss of the dfferent types of logstcs servces markets s provded and the noton of organzed logstcs servces market s presented. In secton three, the dfferent coordnaton polces are descrbed and evaluated. Fnally, a case study, based on the Italan dstrbuton network of two automotve companes, s presented and the man fndngs and results are dscussed. 2 LOGISTICS SERVICES MARKETS In ths paper, two man dmensons are used to characterze logstcs servces markets: collaboraton and ndependence. In partcular, collaboraton can be defned as the process wheren the market s actors work together to acheve common goals (wn-wn condton). Whereas, ndependence refers to the decson-makng autonomy of the market s actors. Referrng to transportaton servces, three dstnct actors are dentfed: ) supplers, whch have to delver products to one or more customers; ) customers, whch requre products from one or more supplers; ) 3PL, whch provdes the transportaton servce and coordnates logstcs flows between supplers and customers. Accordng to both the collaboraton wll and the ndependence of the actors, dfferent structures of logstcs servces markets can be dstngushed, namely pure market, nternal market, herarchy, and organzed market. Moreover, on the bass of the degree of collaboraton, dfferent coordnaton mechansms can be adopted to manage logstcs flows nsde these markets. In pure markets all the actors are ndependent and no collaboraton among them occurs. In ths case, logstcs flows are coordnated accordng to the needs and expectatons of the specfc customer-suppler relatonshp. Herarchcal structures and nternal markets [27] are characterzed by dependent actors, belongng to the same organzaton, whch are, then, requred to collaborate. In both of these cases, logstcs flows are coordnated n order to acheve the nterests of the whole system. In partcular, n herarchcal structures coordnaton mechansms are based on a sngle decson maker. On the contrary, nternal markets are coordnated through multple-decson makers on the bass of the market-transactons nsde the organsaton. The last type of market s the organzed one, whch s characterzed by ndependent and collaboratve actors. An organzed market can be defned as a hybrd organzatonal system between market and herarchy where actors collaborate n order to acheve common goals. Accordng to the dfferent collaboraton degree among the actors, dfferent coordnaton polces can be adopted to manage logstcs flows. 3 COORDINATION POLICIES EVALUATION In order to desgn and manage an organzed market of logstcs servces, the coordnaton mechansm consdered n ths paper s the consoldaton. In partcular, two types of vehcle consoldaton are dentfed, namely nternal consoldaton and external consoldaton, wth only one type of vehcle. Internal consoldaton occurs when the 3PL consoldates the products that have to be delvered from one suppler to two or more of ts customers. Instead, external consoldaton occurs when a 3PL consoldates the products that have to be delvered from two or more supplers to ther customers. Three coordnaton polces are consdered on the bass of the collaboraton degree among the actors: total collaboraton, supply-centered collaboraton, and no collaboraton. In the frst polcy total collaboraton among customers and supplers occurs and drect trps, nternal consoldaton, and external consoldaton are adopted by 3PL. In partcular, drect trps occur only when the total amount of products to be delvered from one suppler to one customer s equal to or greater than the vehcle load capacty. Internal consoldaton s eventually adopted to convey the remanng products that have to be delvered from each suppler to ts customers. Successvely, f some products from more than two supplers have to be stll delvered, external consoldaton can be adopted. In the second polcy collaboraton among a suppler and ts customers occur and both drect trps and nternal consoldaton are adopted by 3PL. In partcular, drect trps occur only when the total amount of products to be delvered from one suppler to one customer s equal to or greater than the vehcle load capacty. Internal consoldaton can be adopted to delver the remanng products that have to be delvered from each suppler to ts customers. Successvely, f some products have to be stll delvered, drect trps are adopted. In the thrd coordnaton polcy, no collaboraton among supplers and customers occurs and logstcs flows are managed by 3PL only through drect trps. To compare these coordnaton polces a model s developed to evaluate possble solutons n terms of benefts and s. The benefts are manly related to the reducton of transportaton sustaned by the 3PL, and dependng on the route length of the vehcles. However, to acheve ths reducton, the 3PL has to face s, such as a the coordnaton and the servce lateness. Then, to explore solutons and determne a negotaton between the actors, trade-offs between benefts and s are needed. Coordnaton depends on both the communcaton channels actvated and the number of messages exchanged to carry out a specfc task [28]. In ths model coordnaton s evaluated as the 3PL s effort necessary to work out the servce needs comng from all the actors n order to obtan a specfc soluton, represented by the route selected to satsfy all the actors servce needs. Then, the coordnaton s strctly related to the number of servce requrements, whch on turn depends on the number of actors nvolved n the coordnaton polces. In fact, a one-to-one relatonshp between the actors and the servce needs s assumed. Servce lateness s related to the delay that can occur for delverng products to a customer adoptng supply-centered or total collaboraton compared wth no collaboraton polcy. Ths depends on potental loss n terms of operatonal and economcal performance. In the followng a heurstc algorthm s developed for a supply chan stage n order to determne the transportaton sustaned by the 3PL n each coordnaton polcy. Then, the coordnaton and the servce lateness are estmated consderng smplfed drvers. Let us assume a supply stage wth m supplers (s, =1,,m) and n customers (c, =1,,n) where q s the average quantty of products flowng from s to c, durng a tme perod and d s c ) s the dstance between s and c. ( - 2 -

3 3.1 Transportaton evaluaton The transportaton, TC, n a tme perod s evaluated as: TC = c t L (1) where L s the total dstance covered to delver products for the tme perod n the supply stage and c t s the untary transportaton. L depends on the coordnaton polcy adopted and on the followng assumptons. The transportaton vehcles are always avalable wth load capacty equal to C. When delvery s completed, the transportaton vehcle s assumed to come back to the suppler from whch t started. All products flowng from supplers to customers can be loaded n the same vehcle and q can be splt out n unts of product. No collaboraton Adoptng ths polcy for each suppler s and customer c, t results: q Y = 2 d( sc ) ntsup (2) where Y represents the dstance covered to convey products from s to c by means of drect trps. In ths polcy the total dstance covered results: L = m n Y = 1 = 1 Supply-centered collaboraton For ths polcy, a two-step algorthm s proposed. Frst step (drect trps) For each suppler s and customers c, t results: q Y = 2 d( sc ) nt nf (4) where Y represents the dstance covered to convey products from s to c by means of drect trps wth full vehcle load. If q C (3) s not an nteger number, then for the remanng products that have to be delvered from s to c nternal consoldaton apples. The total dstance covered n the frst step s: m L DT = Y n = 1 = 1 Second step (nternal consoldaton) For each suppler wth only one customer remanng to be suppled, drect trps occur. Then, let us consder each s wth at least two customers to be suppled. For the nternal consoldaton, s starts the frst trp for supplyng the customer farthest from t (c f ). If two or more customers are the farthest from s, s starts nternal consoldaton from the customer wth the greatest amount of product to be delvered. Successvely, the nternal consoldaton nvolves the customer (f t exsts) whose needs allow to reach the vehcle load capacty or the closest to c f and so on, untl reachng the vehcle load capacty. If two or more customers are the closest to c f, the nternal consoldaton contnues nvolvng the customer wth the greatest amount of product to be delvered. (5) The nternal consoldaton routne contnues snce at least two customers have to be suppled, also f the vehcle loadng capacty s not reached. Let ICDs c f be the total dstance covered for all the trps needed to supply customers adoptng the nternal consoldaton routne, startng from c f (Fgure 1). Two condtons can hold: If ICD + d ( s c ) 2A < d( s c ) 2, then nternal sc f h Γs consoldaton apples, where c h s the customer whch may reman to be suppled after the nternal consoldaton routne has been completed, Γ s represents the set of customers nvolved n the nternal consoldaton routne, qh A = nt, sup q s the quantty of products to be h suppled to the last customer once the nternal consoldaton routne has appled. The quantty of product that cannot be delvered through nternal consoldaton s delvered through drect trps. If ICD + d( s c ) 2A d ( s c ) 2 then, only s c f h = 1 drect trps between s and c f occur. So, repeat the second step consderng the remanng customer closest to s. The dstance covered n the second step s L IC, whch s the total dstance covered to delver products by means of nternal consoldaton routne and possble drect trps. Then, n the supply-centered collaboraton polcy the total dstance covered results: L = L DT + L IC (6) C = 10 s 1 c 2 (q 12 = 5) Fgure 1. The total dstance ICDs 1 c 1 covered adoptng the nternal consoldaton routne. collaboraton For ths polcy a three-step algorthm s proposed Frst step (drect trps) The frst step s the same as n the supply-centered coordnaton polcy. Second step (nternal consoldaton) The second step s the same as n the supply-centered coordnaton polcy except the quantty of products that cannot be delvered through nternal consoldaton ( q ). h c 4 (q 14 = 3) In fact, n ths case, t can be delvered through external consoldaton. c 3 (q 13 = 7) c 1 (q 11 = 5) ICD s1c1 = d(s 1 c 1 )+d(c 1 c 2 )+d(c 2 s 1 )+d(s 1 c 3 )+d(c 3 c 4 )+d(c 4 s 1 ) - 3 -

4 Thrd step (external consoldaton) The external consoldaton routne starts from the suppler s wth the greatest q. Let us fnd the supplers s k wth remanng products q to be delvered to the customer c k shared wth s. Among these supplers let us consder the closest to s. The routne may nvolve two or more supplers snce reachng the vehcle load capacty or consoldatng all the supplers. If t nvolves more than two supplers let us consder the suppler closest to s k. Let ECDs be the total dstance covered n order to supply all customers adoptng the external consoldaton routne, startng from s (Fgure 2). Two condtons hold. If ECD + ( ) 2 < ( ) 2 s d s zc B d sc, then external Ω sc consoldaton apples, where sc represents the set of supplers wth remanng products to be delvered to c after the nternal consoldaton routne, s z s the last suppler havng to supply c, Ω e qz B = nt, sup e q s the z quantty of products to be suppled to c by s z once the external consoldaton routne has appled. If ECD s + d( s ) 2 ( ) 2 zc B d sc, then drect trp Ω s between s and c apples. So, repeat the thrd step consderng the second suppler wth the greatest q. Let us consder the case n whch supplers have no common customer. Then, f d ( ssk ) + d( chcr ) < d( sch ) + d( skcr ) and q + qkr C, then external consoldaton routne apples, nvolvng s, s k, c h, and c r, where s and s k are the par of closest supplers; c h and c r are the customers to be suppled by s and s k, respectvely. Else drect trps apply between s and c h, and between s k and c r, respectvely. The dstance covered n the thrd step s L EC, whch s the total dstance covered to delver products by means of external consoldaton routne and potental drect trps. In the total collaboraton polcy the total dstance covered results: L = L + L + L (7) s 2 s 1 DT C = 10 IC EC ECD s1 = d(s 1 s 2 )+d(s 2 c 1 )+d(c 1 s 1 ) c 1 (q 11 = 5) Fgure 2. The total dstance ECDs 1 covered adoptng the external consoldaton routne. 3.2 Coordnaton evaluaton The coordnaton, CC, s evaluated as: CC = c c I CE (8) where I CE s the ndex of coordnaton effort and c c s the untary coordnaton. I CE can be estmated as: r N Rt! I = (9) CE t= 1 2! ( N Rt 2)! where N Rt s the number of servce needs comng from the supplers and customers nvolved n the t-th trp to the 3PL n order to satsfy ther needs (Fgure 3); r s the total number of trps defned by the 3PL n each coordnaton polcy. 3PL Suppler Customer s c k Fgure 3. Scheme of the 3PL coordnaton effort n the case of a trp nvolvng two supplers (s and s ) and one customer (c k ). 3.3 Servce lateness evaluaton The servce lateness, SLC, s evaluated as: SLC = c s I SL (10) where I SL s the ndex of servce lateness and c s s the untary servce lateness. I SL can be expressed as: t q I SL = [ D( s c ) d( sc )] (11) t q t where t s the generc trp that takes place when nternal or external collaboraton occurs; D( s c ) s the dstance covered to delver products from s to c, n trp t; q s the quantty of products delvered from s to c n trp t. 4 A CASE STUDY Requrement Trp t Decson-makng Trp t: s -s -c k The Italan dstrbuton network of two automotve companes (A and B) has been consdered as a case study. The part of the network of each company, that has been consdered, conssts of one dstrbuton center supplyng three dealers located n dfferent ctes n the Northern Italy. The dealers of company A and B are located n the same ctes and, then, for the sake of smplcty ther recprocal dstances are assumed equal to zero. The dstrbuton center s A supples the dealers c 1, c 2, and c 3, whle the dstrbuton center s B supples the dealers c 4, c 5, and c 6. The logstcs servce, n terms of transportaton, for both company A and B s managed by the same 3PL

5 In Table 1 the dstance (expressed n km) between dstrbuton centers and dealers are reported. s A s B c 1 c 2 c 3 c 4 c 5 c 6 s A s B c c c c c c Table 1. Dstances [km] between dstrbuton centers and dealers. The average quanttes of cars flowng each week from supplers to customers have been estmated and are shown n Table 2. collaborate. For these dealers, the servce lateness related to the delay n obtanng products s avoded adoptng drect trps. In the total collaboraton scenaro, assumng no collaboraton for only one dealer at tme, dfferent collaboratve scenaros can result. In Table 4 the s for each scenaro are shown. Collaboratve scenaro collaboraton wthout c 1 collaboraton wthout c 2 collaboraton wthout c 4 collaboraton wthout c 6 collaboraton Transportaton Coordnato n Servce lateness 2589c t 10c c 173c s 2598c t 13c c 372c s 2589c t 11c c 173c s 2669c t 13c c 385c s 2558c t 15c c 465c s 2589c t +10 c c +173c c 2598c t +13 c c +372c c 2589c t +11 c c +173c c 2669c t +13 c c +385c c 2558c t +15 c c +465c c c 1 c 2 c 3 c 4 c 5 c 6 s A s B Table 2. Average quanttes of cars flowng each day from dstrbuton centers to dealers. Transportaton, coordnaton, and servce lateness s of ths smplfed supply stage are evaluated accordng to the prevously developed model. In Table 3, results are shown for C = 10 cars. Coordnaton polcy No collaboraton Supplycentered collaboraton collaboraton Transportaton Coordnaton Servce lateness 2740c t 6c c c t +6c c 2589c t 11c c 173c s 2558c t 15c c 465c s 2589c t +11c c +173c c 2558c t +15c c +465c c Table 3. Costs evaluaton for dfferent coordnaton polces. The results show that movng from no collaboraton to total collaboraton transportaton decreases. Ths reducton s due to the adopton of nternal consoldaton, n the case of the supply-centered collaboraton, and of both nternal and external consoldaton, n the case of total collaboraton. Nevertheless, coordnaton and servce lateness s ncrease. Then, even f total collaboraton brngs to lower transportaton, ts adopton has to be subordnated to the evaluaton of the coordnaton effort requred and to the lack of servce responsveness. Consequently, trade-offs have to be consdered. Beng the dstrbuton network charactersed by specfc untary s (c t, c c, c s ), usng ths approach the 3PL can evaluate whch coordnaton polcy s more sutable to be used n order to desgn and manage the organzed market. However, the dfferent coordnaton polces are based on the collaboraton among the actors, whch cannot be necessarly acheved. In fact, for nstance, actors, such as dealers, can decde to do not collaborate, because the servce lateness, n terms of lack of responsveness, can contrast ther own nterests. Then, t s mportant to dentfy what can occur when dealers do not collaborate. In the case study, we compare the s n the case of total collaboraton polcy wth the case when a sngle dealer affected by servce lateness decdes to do not Table 4. Costs n dfferent collaboratve scenaros. In these scenaros s change. In partcular, the transportaton ncreases and the servce lateness and the coordnaton s decrease. The servce lateness for the not collaboratve dealers s assumed to be equal to zero. However, n ths case t seems reasonable that the untary transportaton wll ncrease for ths dealer, because of the growng of the supply n ths market. Then, a dealer may decde to be collaboratve or not accordng to the trade-off between ceasng and rsng s. In Table 5 the servce lateness for each dealer s represented n the collaboratve scenaros. Customer wthout c 1 Servce lateness wthout c 2 wthout c 4 wthout c 6 c 1 72c s 0 72c s 0 72c s c 2 93c s 93c s 0 93c s 93c s c c 4 220c s 0 220c s 0 220c s c c 6 80c s 80c s 80c s 80c s 0 Table 5. Servce lateness for each dealer n the dfferent collaboratve scenaros. As shown n Table 5, the decson of a dealer to not collaborate affects the servce lateness of the other dealers, such as for c 1 and c4. In fact, when one of them decdes to not collaborate, the servce lateness of the other ceases. 5 CONCLUSIONS In the paper the analyss of the dfferent types of logstcs servces markets has been provded. In partcular, the noton of organzed logstcs servces markets has been ntroduced referrng to a supply chan stage. The organzaton s acheved by means of coordnaton polces, based on the consoldaton of logstcs flows and on the collaboraton among the actors of the supply stage. Moreover, a model for evaluatng the trade-offs between the benefts and the s of the coordnaton polces (namely, no collaboraton, supply-centered collaboraton, and total collaboraton) and the nfluence of each collaboraton level has been developed. Ths approach permts to explore the opportuntes to enhance logstcs servce performance as the degree of collaboraton among actors of a supply chan ncreases. It s useful to hghlght that the model, based on a heurstc algorthm,

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