HD28 .M414 \ ALFRED P. WORKING PAPER SLOAN SCHOOL OF MANAGEMENT SUBCONTRACTING. COORDINATION. FLEXIBIUTY, IN AGGREGATE PLANNING AND PRODUCTION SMOOTHING Lode Li Sloan School of Manage me nl. Masitachusetts Institute ofTechnology and Morton Kamien J I.. Kellogg Graduate School of Management. Northwestern Unwersity #202e-88 MASSACHUSETTS INSTITUTE OF TECHNOLOGY 50 MEMORIAL DRIVE CAMBRIDGE, MASSACHUSETTS 02139 .^'f 3 >?««.!»=:„ SUBCONTRACTING. COORDINATION. FLEXIBILITY, IN AGGREGATE PLANNING AND PRODUCTION SMOOTHING Lode Li Sloan School of Management, Massachusetts Institute of Technology and Morton Kamien JX. Kellogg Graduate School of Management. Northwestern University #2026-88 Subcontracting, Coordination, Flexibility, And Production Smoothing Mcirtnn .1. I. In Aggregate Planning Kaiiiirn L. Krllogfc C'rafluato Srlionl of Maimfjciiicnt Noitliwostci'ii University Evanstnii. Illinois 00208 Loflr Li Sloan Sriiool of Mana^cnirnt Masparlinsctts Instituf'^ CaniluKlRr. A]iiil, f>f MA T<"rhnolopy 02139 1988 Abstract W(" ])ropnpr a moflrl in wliirli sulirontractinp ran planninc; ?tratop;y. The ])o<;sil)lc iiiarkrt their transaction rnsts are discussetl nisnis in whirh films rofirdinate inerlianisnis if cost fmictions tory, lie cxi'licitly and non-market sulieontrarhnj^ inechanisnis and We show that a set of feasible theii- jirodiirtion the transaction costs are e(iual. ability in jiroduction ai-e derived suhmntraetins nierha- via snl)ronti-arts rar(~to-(loiiiinates other We then study an exanii)le with (jnadratic and a rnnrdinrtticn snhcontract; linear decision and subcontracting]; consiflcird a? a jirodnction In the exanii)le, rules for jiroduction. inven- suhcontractinR n'duces the vari- and inventory. The same interpretation can be used manufacturing resources. for Hexibility of 1. Introduction Suh'-nntifirtiiif: proflnrtioii make the prime cnntractdr's in nn item or srrvice "tlic pinciirciiuiit of is ciwii spcrifirationp availal)Ie to the sn])pliei' can be integration, anrf horiz.ontal vertiral self-sufficient in its all (.1. icciuircs wliicli Day S. is iii>riii;\lly ra]i;il)In tlir of ("roiKimir cnntractor to iniiiic Desi)ite a hiRli degree of hotli (195C)). very doulitfnl wlietlier any mo'lern business enterjjrise is it and facilities wliirli Even ignoring the activities raw materials and the of ])in-ciiase use of distribution systems to dis])ose of Hnal j)ro(lucts, most comi)anies ajijiear tn dei)eiid u])on other ])rodiicers for- dependence, this jierformance of "th(~ some work and least at extii-mely im])nrtant role that subcontracting ])lays in industry has been (Sammil ami Kelley recogni7,ed in the past few years as never before" many oliservers (Williamson (1985), Piore exti^nsively used in the industries firms, etc.) and Sabel (1984)) and/or industrial where manufacturing technologies have for i)oint out that subcontracting adjustment of labor force plaiming (Holt Bitran and Hax et size, (1900), al. (1977). etc ), little Sobel (1971). has been said into the production ])lanning models. al)f)ut among subcontracting In particular, as. strategies holding inventory, Despite the ennrmous work on aggregate pricing anrl jirruiiotions (19!38). more H(-xibility increases an imjiortant o])lion is other ]>r"duction smonthing strategies such Manne is to reali/c greater value of flexibility. lie|j)s aggregate production and cajjacity jilaniung (Schroeder (1981)) fcir Because gicatei- flexibility. has also been long recogni7,(vl that subcontracting can be user! as a sulistitute hi particular, (198(1)) rlistricts (.lajiaiK-se tr)ol makei's, Italian textile the feasibility of subcontracting while subcontracting It Reflecting the extent of servi(es. how Thomas (1971). Hax and Meal (1975), to formally incorjiorate subcontracting I'nlike the alternatives such as invent(]ry and adjustment of jiroduction cajiacify, the feasibility of subcontracting dejiends not only on the decision of the firm itself, interests. but also on the willingness of other, jiossibly c(un])eting. firms The shift from in-plant-))riiduction to milside economic institutions empbiyed by firms We want We to sniirces who may have indicates a major shift more title of between "make-oi-buy" decisions and "make-oi-subcoiitract" Vertical Integration are For examjile, Toyota relies more of design decisions to lay the efficient on many small firms for the s\i])])ly of ])arts those small firms are frecpiently namefl as "sul)contractors". subcontracting relations of this kind can be treated relations with raw material supjiliers. subcontract'' decisions we decisions. which imt is in the How<'ver. same way products which are regularly prorluced w(-ll in their own 1 facilities Firms From the length inider of a firm. on a ])ermanent basis, aud managing the jiermanent as that the ciincern "f this as \\iv subcontractors. in boundary ])ai)er. refer to in this jiaper are tactic or operational decisions the dynamics of the jirime producer as the strict definition. viewpoint of ojierations managemiMit. the former that WilliamsDii (1985) discusses the in markets and/or relational cmitracting. to em]ihasi7,e that subcontracting discussed in this pajier has fhfferentiate conflicting of managing the The "iiiake-or- which depend on conti'act out parts or final on a temjiorary basis due to certain ''phorks 111 or s]i(it-iiiai'kct tlic s]int-c(iiitrartiiif; we In this ])a])cr, iiip: show Wc use a dyiianiir first iirof^raniiiiiui:: ways ])ossil)le namely, the a ])artirnlar set of subeoiitrarts, apjiroach to ilhistiate ordinnticn subcontract via the subcontract. niiniinizeil more desirable than any other subcontract, socially production j)laii can be determined our in the rfinidinntinn snbcontrartinp; can be (1900) and [ilanniiij^ morlcl, The example als<i and hence, contribut(>s method (liven a i-asily inclurletl ccinal We also Here, a ro- contractor and ])riiiie of subcontractinp;, the o])timal model We into Holt. Modi?liaiii. Mutli tjir then slif)w linear decision rules are obtained for juoduction by an example that Variability is and Simon and subcontracting. i-educcs the variability in jiroduction to jiroduction siiioof hinp;. . Moreovei', the riuiiiliiintinn subcontracts arc ctiiice])tual shows that subconf ractin<: tlic fcapil)iiity suhront raets. Pareto-doiiiinatcs rnnn///;afi'ijj so defined that the joint ])ioduction costs of the is how to ])rodiire a feasiMe snl)rontrart any other subroiitrart, assninint^ the transaction costs of suhcoiitractiii!^ arc subconh'actor are tlic ti-aiisar tiniis. fletenunied and the is dismssril in this piipcr arc cither i-;irts fnriinilatc a ])rofi\irt ion ])lanniii)^ iiinfici tliat (-X]>hfitly rcmsidcrs puhcoutract- as a ]ilaniiinK tool, of a siibenntrart Alsn. snliront ('iivirninnnit flir ofoiioiiiic and inventory, smaller as the correlation of the production requirements and the subconti-actins costs decrease, 2. A Conceptual Planning Modpl with Subcontracting In this section, The main subcrintractiiig oj)timality all we introduce a to discuss the issues rec^arding and illustrate concejits of feasil)ility, imrjiose of this section and dominance relations the decisions that dynamic prop;rammin^', model liav(^ is to develo]) W(- adojtt vei'y <;en(~ral notation to incoi-porate of subcontracts been discussed jiroduction in th(" ])lanninfi: literature but do not sjiecify rigorous mathematical assumjitions to assure the existence or uni([ueness of a solution. we take a unitjuc solution for granted. For sim])lirity. we assume there also In effect, two ])roduction are only organiz.ations in the market, and the insights devfdoped in this section can be extended to the situation witli Two more firms. j-irorluction organi^.ations, firm < duction rcfiuirement stream, {D',.\ assume that the technologies 2"s of th(^ production rcfiuirement with tion i:ilanning setting, firms its f and 1 2, < T) ? . are in the market, each faces a frirecastcnl jiro- = 1.2. two firms are good substitutes, jii-oject tlic information and capacity constraints tlic t. where /,' is iin-aniiig. firm existing technology and vice versa. work For i As I - 1.2, iilaniii!: denote by jieriod {P,'.!',) firm ran fulfill firm in the tyjiiral jiroduc- force sizes. jH'oduction rates, overtime, invfMitory levels in an aggregated iH-oduction unit for each jieriod For subcontracting to be possible, we t undertime and based on the current Ts decision variables in a vector of the decision variables which directly affect the jiroduction cost of next jieriod and T/ period cost. Typically. is /,' a vector of the decision variables whicji rlo not directly affect tlie next may include inventory levels by the end of jieriod 2 f and work force size at /; PI )n^y inrhuic innihirtidii cost vn\ the variHl)les in is vari;il)h's ;iik1 rniistraiiit and tion , must state vai'ial)!es D], we assume + / C.','_^, 7/ ( information (or /; , for ) = j the us(^ the set of rdiistraints that the docisioii Ix' ej(f,'. /,'; DJ, /,'_, To ) ca])aeity , (Usniss the produc- tlie minimal same tlie The discoiuit factor That exi)ert(-d /? (0 < /? < We 1). For sim])licity. each firm has (omiiletc information is. and historic state variahles (ivquirements. inventory same belief re;;aidni5^ future re(|uirements, f^iven the forecastinp; nu'thod) Ix- is can he determined recursively , This assumjition achieved through h'arniiiK, Moreover, the sniicontractinf, mechanism tnithfiil resjionses (see Le 1,2. '^^/i cui'rent and share ), " assume that firms know v/c t. show that to However, complete information may tionships. t a situation with comjihte information data, work force sizes, etc > whifh on the next ixni'ul effect of on ronchtional on histoiiea! information aliout the i)roduction 1 ahout each others cost functions and availal)ie /,'_i) tli(^ satisfy, for exaiii]i|e, the iiiveiitdiy liahiiice ciiiist raiut siil)rontrartinp; derisions in ])eiifid dynamic proj^ramminK use /,'. Lot the jtnuhirtioii rost of jieiiod etr. requirements, denoted Ly will Let /;,(r/. /,, produrtion costs from total i;itc, ovcrtiiiic. aiifi iiinicitiiiic. may itself Hurwicz (1072), Myerson (1979). and may sig;nallinf<, l)c too striui^ent. and long-term I'ela- jirovide incentives for firms to give also Section 4 for more discussion on tlie i.ssne). essence, siihcontractinp Ill a snl)roiitract as a Qi jirire a reallocation of jiroduction reipiirements and quantity jiair [pi.Qi] \hc subcontracting quantity from firm is U Qi > firm 2 0. and firm trivial sulicontractiiig in firm 2 gives the will is subcontracts 2 which firm 1 same amount back 1 dejieiid to firm —Qt \{ I to firm The 1. 0) jiart We 0. of may define and i)ric(> its rule nwt the jirorluction to firm 2 and exj)licitly costs of subcontracting Subcontracting We subcontracts ([uantity Q, to I Q( < firms the sulicontractiiig is firm re., 2. to firm (> />( subcontracts a certain eliminate this case as an ojitiinal solution parties. \vlier(> among we introduce later incur additional costs to both Following Williamson, we categorize sul>contracting costs into jihysical costs (which usually on the sul)contiacting ([uantify Q/) and transaetioii costs Ti(Qt) (T,(0) = n), includ(-s subcontracting quantity includes time and in the shi]uiient, handling, arldition to manpower engineering and monitoring costs of the production costs. recjuiri-d for Th<" variable costs, denoteil by The ti-ansa<'tion costs, fleiioterl by F,, generating and im])lem<'nting a subcontract (negotiation, bargaining, comjMiting, drafting, and safeguarding against opi)ortuiiism, etc). There are many jiossibie ways to generate a su])coiitract negotiation and bargaining for an agn-einent. a (subcontracting) meriianis/d. firm 1 intends to sul)contract The It following We is , ranging from a simjile market game to call a jjarlicular way of producing a subcontract an examj'le of subcontracting iiu'chanism, Sujipose asks firm 2 to submit a liid /), Based on the subcf)ntracting ])ricc jif. firm (irriciop 1 how to pul)roiiti;\rt vi;i tin- fullowiii'^ prdRraiii. iiinrli rl(r;.i;:D^ - Q,. mil. if + JuQ, + TAQ,) ,) -^ .dl ftf'!, . ij) r,'.i;.Q, oAr^.il.D] -Q,.i]_^)>{y .^.t. Drnotr the solution of tlir ])ro^r;vm hy r/(7'/), l}{]>i)- a function of state variables, but subrontractinK prire mm Q,>(). j>f romitiufi; c^r^.Ir.D^ wo omit them on - lli) f 'citaiiily, Qi(j>t)- Firm for notational sim])li(ity best resjionse of firm tlie 4 QiiPi). -md ViQiipf) + the solution 2 then ran is also set the to the jirire. Tims, firm 2 solves 1 + T,{Q,{pi)) pf'Uiillil'')' ^t) r/.if.r< g^ir^.llD^ + Q, {}>,). ll^) > s.t. Siipposr /)* is for a and quantity it n. Then, a sulirontrart tini' would aeeejit The rorresiuiiiding optimal produetinn derisions determined is name rould I (H course, a prire and that ])iire at subeontraet geniMateil by Qii}'*)) deteiiinned ac<'ordm(^ly. is subrontrartiuR m(~rhanism (indexed by sjierified in the {]>' For examjiie. firm juissible then firm 2 rould res])nn(l with the (|naiitity hi general, > with subcontrat meel anisms for suljeontrartinp; are Jirire ;», the optimal in the alxive jtroRram anfl the ]>roduetion jilan (for jteriod f) otliei' n, .S"). tlu' resultm(.r costs denote by w(- and Qf the ;i^ merhanism and by foi' both T/" . /,'" the jiarties are where Note th;,t C','- exrlude the transartion costs F, sinre they do not affert the optimization and hence, can be treated separately. Obviously, a subccHitract without subcoiitractin',';. is feasible if it yields each firm at To establish the no subcontracting^ most the cost sf;ifus tpw. we it rould be smr solve the following of two programs. Program i: .r7,(r;./;.D;./;_,)>n. ,..f. for i = 1.2. aufl flenote the Definition 2.1. A Definition 2.2. A I = subcontract subcontract is fe,Tsj7./e if is C','*. Q]^ ^ and Cp < fra/jsarhojia/Zy frasi/i/r if (",' Qf / for (1 i = 1.2 anrl (V,^ + F, < r;," for 1,2. The (see minimal costs by feasibility, in fact, follows directly Luce and Raiffa (1957)). For a fixecl from the notion of iiiiUviiJu:il ratin/i;i/ity of subcontracting mechanism S. a ])roduction game theory jilan can be derived via the to set nil the !>tntus deeisious followinj-^ sulirontrart C] = ri'rnisivc r(iiii]iul at ion followiii>; (']' <]iin. tin- si)erifie(I i\il<-s in , < f> — t 1,7 = above prorednre. On let W(- liave fixed = C,' period = 1.2. We That set th(- is, meclianism .S'' if = 1,j (']^ the If . Otherwise, 1.2] mechanism This mechanism let dominance .S'' lar^c relations C]^ if may feasililc mechanisms can be very dominates mechanism .'^ < C]^' neith<'r firm prefers S' to S. moment transaction costs aside for the - f and obtain next establish certain mechanism say a iloiiiinates •S' We 2 n'jieat the jirorednrc. the otluM- hand, the set of feasibh- subcontractin-; amoHR snbcontractinK mechanisms We i and 1 aiul I imply firms cannot find a transactional and any ^wcn mechanism may not be the "best". for - / the snlirontrartinj^ rloes not it < E\(V,^\D',.k Prnprams and cniresiinndinK jirodnrtion snlirontraet in^ nuTlianisiii 1.2). (lO liark to be transactionally infeasible. However, merhanism. tlie Hist solve t. siilxont ract tlic r(iiii]iiite transact ionally feasible, tlien is ElC^y \D\ In the Sernnd, Foi- rarli ])cri"d Let us look at a set of snbcontracts generated as follows. First, solve a jiropram. Program 0: mm s.t. and let f^i' C]'^' Lemma rrnnf. = ,],{r;. /;. and C^,' (''," 2.1. 0. ' ci{r;'\i;'': D] < d] - Hr)Q,. /;_,) solution coustitutefl by assertion in the lemma th(- - + n^)Q',' r;^,) nii'l ('',' C','* + (",' < T,{Q'/) C'/'^ is + + (^J^ follows immediately at a feasible solution to Pi-op;ram Definition 2.3. A sulicontiact quantity are determiner! by Qi is = _ c^' - 0{cr + ;i^ 1 = , Q; which i. 2. valuables with sujierscript /?^';, ,(//''. Ij''). miy fi^r and Pro^iams Similarly. , is C'/' 1 and any Qi 4 '"', 2 ])his sum rj' f) is ;/ir,-ii,-i7ij.s;;j evaluated Qi = 0. anrl since h[\) 4-^(2) if tlic a feasible at hence, the = Program m(Thanism subcontracting i)rice and - rf _ ) (1 - o)((:r + r.J' first 0) evaluated constittited by the solution (generated by is S. a feasible solution to the value function of is + Cf"' = ("ertalnly. r/^"* su/uo/jfr.-irfjn/' 2 jilus cancelled in the (\ be the . the optimal solution of the jiropram, at called a rc)nrdin:itif<ii subcontract Q',' /^^•;+, (/;./')) the value function of Pioi^ram o])timal solutions to (noticing in (2.1) that transfer value. (;/• T,{Q,) f n. d(~cision feasible solutions fo Proi^rams In jiarticular. > + be firm Ts cost function evaluated CJ' + Cj' Note that the ProRram f{r.)Q,.ri,) be the ojitimal value. corres])ondin<r o[itima! solution, i.e., - }_^{r]ir;.!;.D] - c ;-) - (cf - cf-) and < for n It if fl can < Qi' < f) easily vcrificfl the siilirontractiiip 1)0 and < (^,' niauipulatiou to Lemma ^- 0. (// if 1 * f', if > Q/ siiuo hy iniiinc'rafivr is costs iiioic to produce luoic. it < that Cj' iioticiii;', Also, C^]' takes it ' little f^et Tlir tntal casts t« firms 2.2. ])ri((' mid 1 2 uinlrv a fonidinntion suh'-nntiHrt with pnrnmrtci are cr = - ('V (i In fact, to obtain a cotnihtuilinn suhcontract, ojieratiiiK jirice to with coin])lete coordination as Proposition 2.1. A The Procf^ rnnrijiiuttion siilu-Dntinrt thrm niiy incrhnnisin. first jiart Lemma liy cf = 2.1., f:p. This is is (I'l always thei-e must note that (!' exists a doable since ^ r:,"' +(':f'' = such that ? ('',' Lemma 2 by C,', < C','' > r:p u Fii'st of all, it is a set of are e(jual. Secondly, unlike other subcontractinj_' over, is socially Propcsition is pinjity if 2.2. an J only The a = (2.2). 4 C,',' () . 2 tlmt siiliriniliFirt and I l^y . 2 2. For any subcontract mechanism C-'^ and r'''" C.', = , foi- = C.', _;' r;;' ^ - Set r. — —(",]' < cj' d'^' such that d' c;p if —C!\ = l /? < C', , since undnminated subcontracts mechanism, if wlieth("r the set to test ti-ansaction costs results ni an uni(|ue subcontractinpj minnni'/.rs thr total cusl it if iin- of ])roduction. More- of transactionally feasil^le emjity or not. Sujijiosr tlir trnnsnrtian costs nf coaiiJinnti'iii snhi-ontincts nir less thnn or rqunl to that of any other Prnnf. moic desuable we can use rnovdinntuni subcontractni;; subcontracts Lemma f^cncvAtrd discussion, we can see that the cnn/v/inafion subcontracts constittite an subcontracts. outcome which fincl 1. From the above jKii'tant set of sii}trniitr:\rf wliii-li iIi<iniiiHtcs Thini, under the coordination subcontract with jjarameter 0' again by For a frnsi}<li\ of the proposition follows directly from jiart, mie firm, and then in . exist a rcnKJinntion siiiirontrnct To prove the second S, + cf' — q\iantity by Hist deteiiiiinr snlicontract fiiiiis they were two de])ai-tiiients if divide the total cost savings, ('j' + rr -r,f) -(>){(}' if Q^," j^ siilirfintrnet and + r:/' "if" jiart directly follows . Tlien. the set of ti:ins:irtioiinlly fe:isihle .su/icnjifracf.s df > C',' Proposition + 2.1 F, + To not Fj. n-et tin- the transaction costs in the cost savings and divide C'* +''',* price similar to that in Definition 2.3. j.s — "only if" jiart, we — F\ — amon^ C',^ Fi sim])ly include firms via a I Wc now iiroccrd to fliscussinn alxnit thr ti-ansiictioii costs nhitifl tn diffcirut sul)rontrarting ,i TIk' iiliysical costs of sulicoiiti-iictiiiK nsnally iiicrlia.iiis]iis. sulicontract That ^diciatccl. is is why wc The pi-o(lncc(i. assumption against, the Let ns see in general. effoit general consmisus devoted is tc) tiian single jilant drastically cost more why As we can models. is hard to may reduce liiKh 1 and 2. conce])tual transaction costs. That mij^ht take nnvhanisms not ai-e model. Piof^ram Thus, the comjiutational That more is A lot of flifficult usually not of the transaction jiart However, the jiarameter in the negotiation and bargaining, and Ion;:: as f^tntiis is quo to nail down it This is the of rtuniliii;ifi"u subcontracts. jiartii's. iciiutation effects, or regulations the difficulties of dividing the benefits from subcontracting and lower the transaction moi-(> Williamson (lOST)) mentions that emj)liasis on building an intimate ]M'rsrinal than on drafting and safeguanhng a more extensively on subcontiacting than is contiact rletailed triie in siu-cessful .lajianese iidations between contracting This exjilains The the lhiite<l States, man- why .Iapan(\se rely discussion in this section and proves their success. ju'edicts Subcontracting, Coordination, Flexibility and Production Smoothing In whicli a market mechanisms ipjnore the may have situations, long-term relationshijis bc-tweeii ufacturers place 3. we can not lience, oui' in s])ecify costs of rnnrdiupitinu subcontiactinjr. pai'ties in liave low transaction costs. nuxlerate for the ritardinntinii suhcontracts major cause of high transaction costs many and see, than Piograms way on liow a sulicontract will (li'jicnd moflels and com]iutationally, they jilannin''; firms miglit have to use outcfuiies of other In , the coordiiuition suliconti-acts multi-plant subcontracts citordinntiitn market nieclianisnis tliat in Projiosition 3.2 (Hfficult relativ(^ly is is tlic treat tlic varialilc costs of sul)contractniK as iiiochainsni- Out the transaction costs in<lc])rnilcnt in the aluivc (hscnssion. is do not dcix-nd on the jirecerling discussion, subcontracting in we can cfniceptually. see, We now any jilainnng model us(- a sim]>le thei-e is example no to difficulty in An Example considering show how subcontracting smooths juoduction. Holt. Modigliani. chiction cost function framework ties, in and more it in is Muth and Simon and deiiv a linear decision our discussion because simjib' to analyze, but realistic (1900) projios'- a (|uadiatic approximation of a firm's models. tlie cpiadratic rule for aggr<'gate plainiin''. a])])ioximation avoids ( We ado])t of quadratic costs is that their (uiibinatorial difficul- the (|ualitative insights obtaininl in the framework Another arlvantage ])ro- ])i-evail the optimal solution for the uncertainty case can be obtained directly from the solution of the ceitainty case as long a? the cost function is jiositive definite. this "certainty equivalence" Holt, Modigliani. Muth and Simon j)rf)j)erty in their ('hajiter G. Also, then- is (lOGO) discuss and jirovc evidenc(- that linear rules are optimal or nearly ojitimal not only for ipiadratic cost functions but also for functions (Schneeweiss 1971, 1974). 7 more general cost To avoid rninplcx we further notiitinn, roiistauf aiul lalior a-ljiistiiiciit rosts stage jinuliirtidn for firm rf)f^ts i i. ai<- = firms iiiniut assiiiiir tli:i( Tlicirfor.-. iK^t'liKil'l'- \]\r ;iiii wnik finer Hnll fnllr.wiii;- .! size irlafivM^ly (1900), thr al. 1.2, ate (3.1) whoiT D] is the pnidnctioii rate for ])riiocl t, I] the produftioii rctinirriiient in ])ciiod i, and r,' is W<- ran solve two tlie same apjiroaeh LGmma 3.1. CV-,. '^ = 7. ' I>y I'-vcl the riid of tlir jHTiod (, an- constant cost i)aranif^tcrs. single firm ])rol)lenis .'^ hy invciitoiy flic is F(n- /;. i = t. i Mutli and Simon (lOGD) as in Holt, Modi<;liani. = ? + r; - D] - /;_, In ])artienlar, 1.2, (U{i - + /\,) (-i-(/o - i.-U{l - + /\,) + (^'.,(1 ( -4, - ^_^ ^'r„)l + ^T„. (3.2) (4, ,^^ - A,) + r:4,)(/' ^, - r„)l + d; + r„ - (3.3) 2(-i, if r — > CO. wiif-rr A, (0 < A, < Ij is fiir f'l.A? If - (2r:„ nf i<<<)t + r;4,)A, suhcontrartinp; strategies are eonsideretl, then add more rondjinatorial difficiilti(^s F, = D. ?' = - tlie r'„ = o. (3.4) transaction costs of snlirontracting will the transaction costs are negiccted if This can he a gonrl a])i)roximatir)n when 1.2 By Proposition long-term rolationshij). (pi;iijrntii- r(ju:iti(iii. to the analysis, as ilhistratcd in Section 2 the prolilcm hecoines relatively sim])le assume siuDlIn 2.1, and 2 2.. tlie On the other liand, For ilhistration. we two firms have a good suhcontracts are not rmiy cnnrdinntiitii Therefore, wc always transartionally feasible, but also rareto-doiiiinate any otli(-r can reasonably expect that firms follr)w a certaui r(iniihi>:iti"ii subcontracting mechainsm. By the dynamic j)rogramming juocedure describeil above, for each period are, C, = ElC'i^lD',.!' C} + r.f = < f - E[(^j" l.t + = 1.2). (/ subcontracts. - 1). Thus, the exi)ect(-d future cost ('r\D',..'^ <t-l.t = 8 l.2] = the ex])ected future ccists in E\C','\D\..'' Brogram <t.i = (for 1,2]. t - 1) is Honrp, liy ''(crtainty {•i|iiivMl(-iirc" flir only need to solve argument, in ordci' to wv plan, Mii- i>])tiiiial iiid'lurtioii fiii'l program. tlic fnllowin;', T r^ g,.r;,/;,-=i.2,f=i 3.5) il, + r; - Dj - Q, = Ti{Qi) + T^iQi) ran also hr jirovidrci — assnniin!; that Ti ((^) t-T'2((V) the consideration <\\Q ,? first = t = 1,2 3.C) T. \ hy a quadratic funrtion centered a])]iroxiiiiat(v| with the In coiiiiiarison he ohtaiiKvl still sinjd"' numher snl<contractin<r), this ])roKram has twir(- the r)f Qi's: tlie exjilicit linear decision rnle can The If. at 0. i.e., firm i)rol)leni (witliont of decision variahles p\ns fairly easily. ord(M' conditions yield - r-u(f,V, r,') - r,'„(/; - - r.'ci/;; = q,)) n. (3.7) (3.8) (uP' ~ ^4if'ci(// - r;c,(D,' -Qt)) - <\2Pj (3.9) where P,' = T/ - ("'2,, = (^i - Q> = ^[^^4i(^'Ci)'^' where C = CuiCaif + for in P'l terms of Pi r' + + = Z?( Cn + r7i2. (3.9) to be (3. in) ^'42^'C2/fl. .solvinp; them we have - il-l - ^'22) + - f'lJ/; /,'-, - ^"21) ^41^'0l// + [(^'4i(^'0i)' . Rewrite ^-'5, - ('nP' - (\i<'ui] + (iiP,' \{(\7{(\7? + (\7)Pi + ^'12(A' D^ + Dj - SnhstitutinK (3 10) into (31)) and (3 G) and ("n ^- + where + H /; ''i^P] + (^' + ^'12)(// - //-, - ('21) +c'i2 r.'n Pf = = ^3,72('i,. ;uid /; (42(^^,2)'^; /,'_i. ^- = - Cr42(r:c2)^ and /,' ^'2, ^-11)^^ - + ^'nC? + {( UsiiiK efinations (3.10), (3 11) /,' ^ (-nni' - ili - f>22) - (Ai(\ill + ^Vc2/7l- the total ]Hoduction retinirement in i)eriod of differeure erjuations of (3.11) ^'42^'C2/,^1. and (3.12). / (312) and (' = wr can obtain from ^'AiI/'Ci) (3.7) and +<^m2(^'02) (3.8) a + system as followinp;. ai/;+i - (2r,, + hi)ll + a,//_, + dilf+i - ('/i + 'I7 + <)l! + 'hij-i + ^l = "• (313) «2/7+i - (2^2 + l>2)lf + ^2/7-1 + ''2/;+, - (''1 ^ 'h + ')/; + '/1//-1 +>!? = " (3 14) where + for 7 = 1 . 2 J 7^ . Solving /,' and 7[. methods 7 = (U,('o,D]). linear differeiire etjnatidiis (3.13) tlie and we can (3 14), nl)tain the (h^cision rules for derision rnics for ])i(ulurtinn and sulxdntraetinj^ follow directly. For general of polvinR linear difference erinations. see Miller (10G8) We now for + D',) 7 tlie and - ^'n(^-i,(Z?;+, 1. 2. look at the situation in which firms liave syiiimetiic cost fmictions ;t = ecjuations (3.13) 7. 1 = a and (3.14) is = a,, h h,. d = d, and -= /„ /,;. foi sum and easy to solve. Takuip; the 7 =- 1,2 Let C^ = (7;., Then, the system of rhtfcriiice of (3 13) and (3.14). we obtain the following; two system of dith'rence e(iuations, where V, = // + (a + d)U,^i - (2(a + d) + h + r)ir, + (a + d)U,_i + A] 4 [a - - (2(a - d) + // - e)V, + (a - r/)r,_i If r/)V',+ i and V, = // - Each /,' of (3 IG) and (3 17) is = 0. (3.1G) + A\ ^ A] = 0. (3.17) /I; a sin<.dc varial)le linear differenrc efpiafions which can he solved easily. OhserviuR that ri + r/= <\{2{(U((\? -^(\) 4 (>^) + f'n). + r = (UW('i{('<if + n- d = h ('i{2{(^i{(\f 4 ^'4^'c) b-r. = (',{2ni and etjuations (3.11), (3.12) Let X and A* lie and + f-n). +(';n). we have (3.10). tiie folhwin;^. the smaller roots of CiA^ repjjectively. f'l) Note that A = A* when - f'n (2r;i = + Ci)X -r, = OO. 10 n. (3. is) Lemma 3.2. F<>r i = 1.2. oc + = ^'' ^'i(/n-f'5)l + c;,(2-\) + - (r:,(l r;, - A) f's. (3.2(1) E^''^''^^'+^ - ^i+i) + ^*<'oDU (^,){I„ -I ^ + aD] + C,)] (1 (h - n)D] + C2 f (3.2i; 26i "^ 1 (3.22) ifT — > oo. w/jnr'- A ;s tlm suinUrr nu.f of (3 IS), fm = ?' J. 2. j 7^ 7. (3.23) D; = ^ ^ ~ ' <*i, D, p,D\ 4 (1 p,]Ol - = -d P, -( + ^'n(^'i(2- A) 2ni(U{c^{(-^ + i)(2_ A*) = + (3.24) r'4) + rn(r:,(2- i) ^ Ai ^). for . = .D,.(1-.)P,, v= f > A') + r4)' 2. ^'''^ 2(rMr,)^^r:.)-,r„ ' or cqiiivalrntly. i); = 7,d; + - (1 7,)r/. D; AZ?, = - £>/ D;. Noti(<' that invrntory of firm in (3.3) ami .=!nm of its AD, = ill i - Dj. Z?; the hIiovc in the Iciiiiiia. same vrry :in<l = (\D', 7, = - (\(^cD',. AD, = D] - we liii(~ai' iiiti'iitioiially form as tliosc (3 4) rxrrpt that instead of nsinp only its own demand and the otlier fiiin s demand + /?,„ (! --/?,)( 1 - (3.2G) ,,), (3.27) Dj. write it nsc^ flic in derision nil<s of piiulnrtidii and a siiiiHc-finn own deniand Tiie i>laiiiiiiiK ])r()l)lciii forerasts, firm weip;lit.>! on its 7 a? uses a weighted own demanrls mrreases as the cost of snliront raeting (^'n) increases, the derision rules roiiverge to those of a single firm as ('n ai>]>roarhes infinity, of the two and at tjie in tlieir d(Misioii rules other extreme, firms sim])ly use the aiitjimetic average when C'd = 0. 11 demand Lemma 3.3. zrif fioiii i<< Tlir wrifrJits. r\. of the — two rr'^, { /J,' (nv\D^.Dj] = aii'l firniaiul streams. Proposition For 3.1. /',' , < ^ = whm e(/tja/)7jes hnli} c\njy nf invrntmy nu<I jir"(hirt inn fi/'His f/erj-ease a;)(/ file = j 1,2 tlie first result same exeept same exjieeted as f'd inricnsos is iii(ir])<Mi'l('iit n\\<\ < ;ia Z"/)^' — ;is liy jx'ii"'! to jicTind. /?[DJ] where- p is — ft, tlic ((nrcl.-itioii cooffiriciit fjnfis. "f = 00 ("i, Tlint eiq\']^o. < Vnr\r;''] Var\I\]. I /"ii/if Vnr\ri\. is. si;/i'-finfr;i'-fi/ir^ as thr anlirontrnrtiiif; ens^ js nat icijnrr-s ti<(> liiyli <ir Hirrrases as <iu;\iitity v:iii:i}iihty and jiroiUirtion ronrhitiou corfBcicnt of tlir ilrcrrn^cs. C,',,. simjily nntirinp Miat thr thr ilrnmiiils of thr M<>rr(<vrr. t]\r v:iri:iiirrs of iiivriitnry tlic s^dirontinrtiuf:; cast. oln'imis 1. E\ri"] = E\rii E[ii\. p > t from th'' lules witli ;iiifl witliniit siiliroiitrrirtini^ twi firms iiave the for usinp; {hlfereiif (lemaiifl forerasls. hut ii<'maii']s f^r tlie vahie. To prove the seroiifi result, Var\D]\ note that fii'st = Var\P,D]^ = P^Var\D',\ - {\ + Pi)D\\ - (1 p,)''Var\D',\ ^ 2/?,(l rT'-2/?,(l -/y,)(i Sivoiul, nnr linlf to 1 vanaji'T of thr suJx-oiitrnrtiuf; dcinniid. p. (irrrrasrs find are inrirn^r fmin "iic 1, 1} nrc nir imt jirrfrrtly (imsitivrly) rnrirlntri] Proof. Tlie > t Hrin:^ hnvitii^ syiiuurtrir rosf Var\r/'] thr > f . prr^ for —1 < E[r^'] a.u<i f"r nii'l 7,, inHiiity. Appuiiir thnt thr dcinaii'ls Vnr\D',] p, - ~ p ,]< Uw\D', . (2.28) D',\ pW- we rewrite 1=0 + 21=0 Note that we assume iiifiependeure (in(h'pen(hnit of p Far[DJ) is and C^,) inereasinp: in p Vnr\Di] = Vrtr[D;] solely via Far[£)J). if In-twe-eu jieriods and tliat I[ and /," has the same huear form and have demands D] and D] respeetively. By (2.28) and and only C',, if /7 sinee = I /?, or The rnnrlusion with = 1/2 wlien n„ = co (P, = r.',, 1) ^ And and p, is anrl inrreasinR in 12 C'n. Var[f;'") dejx'nrls on p respeet to the jiroduction deeision rule ran proved. Lemma l)e 3.3.. and and Oq similarly To ralruhito the nf vr\ri;iiicc AD, = Q[ note . - DAD,, {2p, tliat AD, = - (r,(27, 1) Thrrofon-. Kar[(yj'] must he soino jjositivc term inultiiilird = Vrtr(AD,l wliicli (Icrrcapps as /) + V nr\D\\ - ^^«r[D;] iiirroaso?, aii'l tlic ])ositivo - (\(\{2p, - 1))AD,. V ar\[\D,\. l)y 2r.'o„[D;. D/j term 2(1 - ^)r7^ dccri'HsiiiK finirtion of C,^. tkw is = Imt I From the jn-oiiositinn. we rnn s(-c tlint siihroiitrartiiic; ran ;il)snrli plauniiiR strategies such as inventory. As a result, hoth iirothirtion rednred. show that we do If more comiireliensive a sulicontractinp; heljis to exercise to inchuh' stal)ili7,e ignore snhcontracting as a jilanning strategy and when corri'lated the case that demands The model we technology. are In examined has the As we mentioned In the first case, when an" ni'gatively coirclatcd liavc good substitutes work force in for the jihysical the output of firms recjuires the other case, the jiresence of flexible" as well and im])lement inter]iret ation we assume ])ossibility force It then, jih-nniiinj;. we can ])articularly costly to is a suhcontract . It is usually the ])roducts of firms are substitutes. if s(>cond the beginning, six.e inventory varial)ihtics arc firms' ])rodiirtion n-quirements arc negatively tln' relatively easy to underwrite is it th<' aii'l work as dci other tlic v;\ri;il>ility to acc(-ss tlie value of flexible Thi'rc co>ild be of subcontracting, two cases. technology that firms currently have. similai- tjie two firms that the technologies of the manufacturing tethnology mak<'s firms aljlc to fulfil jiroduction ref|uiremcnts wdiich need tiaditionally different technologies. Therefore, facing flcniands with traditionally different technology re(|uirements. dcdicat("d t("chnologics but it is it is is iiifeasibh- to have subcf)ntracting with the feasible with the flexible technologies. profluction ])lanning with two departments having technologies, it demands that In the context of intrafirm re(|uire infeasible to cfioidinate the jirofluction reepiirements of dc(licat(-d technologies but it is ti-aditionally different two dejiartments with the feasible to flo so with the flexible technologies Having this in mind, the single-firm ])roblems discussed above re]i|-escnt the o])timal plan with the dedicat("tl technologies, while the nnilti-firm jnfiblem i(^])reseuts the ojitimal jilan with ])erfect flexible technologies, for both inter- and intra-firm situations. We can conclude that the such as inventory and subcontracting to reduce tlie flexibility mills. order. new system flexible speciali^.atifin, as opposerl to standaiflizf^l French and Italian textili^ fiiiiis. Piore and Sabel (1984) rcai'rangements and th(" i)f)int search for and Japanese also a substitute for strategies variability of j)roduction. Piore and Sab(d (1984) ])resent a biilliant study of a system of is tool mass of industrial ])roduction. a ])roductif)n makers are exemjilary American mini of this new steel industrial out that technological innovation, constant subcontracting new jiroducts are the structiuing elements of the systems of 13 In the partinibu- cxaiiiijlcs of Frciicli flcxililr ?]i('ciali7,ation. nf (leiiianci results in tlic nmstant rearrangement <if and Italian textile firms, tlu- variahiiity snlxoutrartin!'; patterns: every jirime rontrartor rtmld becniiie a snluDnt rarf or. every snlirnntraetor a prime enntraetur close roiation? l)etween sulirontrartin<; and Hexiliility Tlie evidenee indicafcs the and between sul)eontrartinK and rnordination of interorganization iM-ndnetion. 4. Discussion Variability in ])rnrluetion recinirements lias added moi-e comjilexity for researrhers and j)rarti- tioners in produrtion ])lanninr: Th(^ sinnnthiiie:. The second first is and srhednlinp; through the second catppory. iiricing. promotion or many ways ai'c in is falls in the second cateiniry Cnnrihuntinji subcontiacts. on and Pareto-doniinate all tlu^ second when the other When in^: twf) categories of (non market) mecha- the numbei- of contracting outcomes l)ut have lf)w trans- hand, yield the most total cost savings othei ]iossible subcontracts, but There are roiitiacl small, market meelianisms usually lesult in less desirable action costs. advance. usuallv im])ossil)le). wjiich a subcontract can be ])rodured nisms. C^onrfJinnt if III subcontracting is (it in r)ther imjiortant strate<^ies in tlie Subeontractin;'; ])lays an imjiortant role I'c-jection j)rn<lticti(m Subcontractinp; as a production itself mechanisms: maiket mechanisms and iclational sul)conti-actiiig parti(^s There are rate(^oi-y to eliminate th(< varial)ility comjiletely fail There which represents j)roflnction of inventory, ns(> thronsh modification of the demand jiattern is ]ilannin?: strategy falls in the stiatepies There are mainly two ways to achieve may Considering hav>- high transaction costs. subcf)ntracting in ]>iofhiction planning, we need a cai<'ful study of the forms of subcontracting mechanisms and thiMr costs Nevertheless, rdoidiuntidii subcontiactinjr can the set of feasible subcontracts To have subcontract to forecast thiur When it is also own in'-'; nonem]>fy and is as a planning question here hi is how s cost clata demand which is is not difficult to do "correctly" than to do In firms o))tain other firms" jirivate information lie iiidu' cs may Firms do not only need in those situations lead to the consensus on inhuiiiation if As we arguecl subcontracting Sul)contiacting recjuires additional coin])utation 14 for if sometimes, each individual firm. Firms r(ii)tili:witii>u they don t subcontract. have it in the The first look for an ojitimal subcontract In befori'. learning is hi jiarticular, truth-telling behavior, naimdy, incentive subcontracts (Huiwic/, (1972) aiul Myerson (1070)) informational losses whether formulated as a game with incomjih'te snludutracting via rtdational contracting, one within a subset of feasible subcontracts which coiii])atible it crucial in determining a subcontracting via markets, the situation can iiiforinatioii. test subcontracting (juantities. liidit" we need more information the prorlucts of firms are good substitutes, this need each other least procluction i-eijuirements but also need the other parties d<'mand informatir)n. easier to jn'edict total industry place, tool, jiroject the at general, firms would incur and re])utation efF(-cts will carried out on a long-term basis. For exam]ile. we nee<l to solve a multi-firm ]A:\u ill WIk-h (U'lor to Bii<! a /'(uirilmnfuni sulicontrart this iiicicHse miiqint 111 ;\t lull is As iii(>i|(m;iI('. in nur tlir i-xniiiplr. saiiK' liurar rule as in sint'lc-fii in i)r('l>lrni aii'l siiii]>ly ic])lacc of the ic^quiromcnts of the two fiims \\'licn the liur'hui of a C(uir(liii:tti<in snl)roiitrart will Ix- numlxT heavy, nuinli'T nf jiartics in cnntrjict aii'l we inn the is siii;ill, src tliat firms nsr tlic very icciiiirciiK-iits ]>\ tlic wciglitcf] sum of jiartics iiicii'ascs. tlu' coiiiiJUtational sonu' sim])lr maikct mechanism may be prefcralilc. rriciiiR tion. a very iiii]ioitaiit stratef.^y is (iiic certainly shoiihl consider in oiKaiiiz.inp; j)rocliic- Kamieii, Li and Samet (1988) study a one-shot piiciiK: ^njuc with sul)contractiiip;. There, we identify that firms to which both firms may use sulicoiil rart mtr as Considering jjiicinp; as means of collusion to achieve a ])rice a stratcf^y in pr'KJuction planning: is more desirable certainly an imi)f)rtant item on our future research ajjenila hi sum, subcoiitractin;^ is way oik- to reallocate prochiction organizations and to achieve ])roduction smoothing; tion costs, and h<'nc(\ is socially desirable firms are requiicd to ex]>aiid There are in this ])aper tln'ir it is Two sip;ned. here could be Sulicontractin<^ usually lowers To incoriHnate subcontractinj' scojk of jilaiiniii': of them aic of most imjxn-tance. Tliese (juality. two Tin- secojirl as])ects is tlieic iiiiKlit The first "mana<z:in<j;" , one is we have not discussed "sourcin;':" and maiiap;inp: ]>rincipal-aj:;eiit . in detail namely, how to to have tremendous impact on subcontracting costs. The criteria etc. Rep;ardins the be nncontrollabh^ uncertainties, jirivate information (in'oblenis subcontracts with the and mechanism jiroduc- namely, how^ to mana^.v a subcontract of aflverse selection), and/or unobseivable actions (])roblems of moral sourciiig; tf)tal into production planniiif!;. on-time delivery, conformance to (-n^ineerinjc s])ecification, economic environment, tli(- to consider other a<';ents in the eroiuuny. ma,iiy other issm-s concf-iniiif-^ subcontiaclinj: practice seh-ct ((jualify) subcontractors. once re(|uuements amoni^ profiuctive ]iossi))le a]i])lications of desipii deserves further research. 15 ha/.ai-rl). How to deal with economic theories such as References ] Bitran, s;n;i 2. Srionrcs. Vol. Day. S -1. Hax, A. Vol. 4. 1, Holt, Work 5. Nn. 8, ('., 1, Dcpifjn of Hicrarrliif and H, C, F I'r<i(lii(ti(iii F^hiiiiiniK Systems", Dcci- 1077, pp. 28-55, Poliry in tin- Aiifr:iin<- ('. Inihi^try. (iradiiati' School of Business Ad- Meal. "Hierarchical hitcpration of Prodnction Phuminp, and Schoiiulnig" ]>y Modipliani, M A North Holland/American Rlsevier, 1075. (;ei,sler. A Simon, F Mnlh, and H. .1 Force, Frentice-Hall, En<;lewood ChfTs. Hnrwicz, L al Harvar'l I'nivrrsity. Boston, 195G. Logisfir^. edited ('. tlic '(^ii Sti}>rniitia<-tinf, , iiiiiiisfratioii, 3. A Hax, (J., aii'l "On hiformationally , nud OrKnuiznt i'<n eds., Drrjsiou N..1.. Decc-ntrali/.ed Amsterilam: and Phinniiif: Picrhirtidii. hn-rntnry. 1900. Systems", hi ('. North-Holland B. Mc('uire rnlilishiii!', and R. Radner, ("om])any, ])p. 297- 33G. C. Kamien, M L. I.. Li and D Samet, ''B<'rtrand fMimjietition with Suhcontrartinf;" . mimer), 1988. 7. Lnce, R. D., and H, Raiffa, (^nwr< nnd 8 Manne, A. in. Economic Lot .lohn Wiley Si/es' , Sons. ^- M:iu:it:rin''iit New York, 1957. Srirnrr, Vol. 4. No. 2. 115-135. 1958, i)p 9. Trofrrammin'.'^ of S., Drr;s;Vi;),s. Miller. K. S., Myerson, R. Lmear Diifnmrr W E<iu:,tionf^. and the "Inci^itive f'omjiatihility B., A Benjamin hic Bai!;ainiii}.': . NY. 19G8 ridhlem", Eennnmetr/V-a, Vol. 47, 1979, pj). Cl-73. 11. Fiore, 12. M .1., Samniet, H., and C F. Sahel, and ,lr. (' (J. Thr Srm,,,} Kelley, Do's liidiistr}:il nii'l from Siil<rnntrnrt M;in:]gcinrnt Hnndhnok. 13 Srhnceweisp, ('. A . AMA('OM. No. 7, M. York, 1084. MHUHgonirnt, oxcerpt(>d 1980, 1971, p]. An Application of Wiener Filtering; 472-483 New York, 1981. "Smoothin;^ Start-1'ji and Sliut-r)own ('osts", M:in:fArmrnt Srirnrr. Vol. J., Sri- 1122-1130. Schroeder, R, (^, Ojirrntions Munncr-mmt. McCraw-Hill. IG. So])el, New 'Optimal Production Smoothinj' and Safety hiventory", Mnnngrmrnt rnrr, Vol. 20, No. 7, 1974, pi> 15, 17, Books, in Snl<rontr:irt Schneeweiss. (\ A.. "Smoothing Prodnction Ly [nveiitory Theory", Mamigrninit Srirnrr. Vol. 14. Dou'ts Dividr. BasK 17, 1971, pp. 78-91 17 Soliel, 1971, 18 M PI). Thomas, .1 , "With Stocji.astic Demand. Infinite Hori/on Case", Mnunprmrnt Srirnrr. Vol 17, 724-735. L. J., "Linear ProRrammiiiR Models for Production- Advertisinr: Decisions", Mana^e- mrnt Srirnrr, Vol 17, 1971 16 6117 U70 19. Wi KUHsnn, (). trnrtiucr, Tlir E.. Thr Ecnnnnw Iu,t,fnt,nns nf Fire ricss, N<-w York, 1985. 17 (::,i„t:<l,.<w: Fnms. Mnikrts. RrlHtioiuil (Um- lo/:J|c>fi Date Due B^st^tm DEC 29 2 i^AY OCT. 198^ ly^JD 23199/ JUN. 09 \m\ Lib-26-(;7 3 TDflD DOS 351 DD^ :< iy.i-w>yimx^iv^^^^