Solutions for Fundamentals of Modern Manufacturing , 5e (published by Wiley) MPGroover 2012
1 INTRODUCTION Review Questions 1.1
About About h!t h!t per"ent! per"ent!#e #e of the $.S. $.S. #ross #ross do do%est %esti" i" produ"t produ"t (G&P) (G&P) is !""oun !""ounted ted for for by the %!nuf!"turin# industries' Althou#h the per"ent!#e h!s v!ried over the ye!rs, "urrently the %!nuf!"turin# industries Answer. Althou#h !""ount for !round 12 of $.S. G&P.
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&efin efinee %!n %!nuf!"t f!"tur urin in# #. te*t define definess %!nuf! %!nuf!"tu "turin rin# # in to !ys+ !ys+ te"hno te"hnolo# lo#i"! i"!lly lly !nd e"ono e"ono%i" %i"!ll !lly y. Answer. he te*t e"hnolo#i"!lly, manufacturing is is the !ppli"!tion of physi"!l !nd "he%i"!l pro"esses to !lter the #eo%etry, properties, !ndor !ppe!r!n"e of ! #iven st!rtin# %!teri!l to %!-e p!rts or produ"ts %!nuf! %!nuf!"tu "turin rin# # !lso !lso in"lud in"ludes es !sse%b !sse%bly ly of %ultip %ultiple le p!rts p!rts to %!-e %!-e produ" produ"ts. ts. /"ono% /"ono%i"! i"!lly lly,, tr!nsfor%!tion n of %!teri!ls %!teri!ls into ite%s of #re!ter v!lue by %e!ns of one or manufacturing is the tr!nsfor%!tio %ore pro"essin# !ndor !sse%bly oper!tions. he -ey point is th!t %!nuf!"turin# adds value to the %!teri!l by "h!n#in# its sh!pe or properties, or by "o%binin# it ith other %!teri!ls.
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Wh!t !re !re the differen" differen"es es beteen beteen pri%!ry pri%!ry,, se"ond!ry se"ond!ry,, !nd terti!ry terti!ry indust industries' ries' Give Give !n e*!%ple e*!%ple of of e!"h "!te#ory. Answer. A pri%!ry industry is one th!t "ultiv!tes !nd e*ploits n!tur!l resour"es, su"h !s !#ri"ulture or %inin#. A se"ond!ry industry t!-es the outputs of pri%!ry industries !nd "onverts the% to "onsu%er !nd "!pit!l #oods. /*!%ples of se"ond!ry industries !re te*tiles !nd ele"troni"s. A terti!ry industry is in the servi"e se"tor of the e"ono%y. e"ono%y. /*!%ples of terti!ry industries !re b!n-in# !nd edu"!tion. edu"!tion.
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Wh!t is is the differen" differen"ee beteen beteen ! "onsu% "onsu%er er #ood #ood !nd ! "!pit!l "!pit!l #ood' #ood' Give Give so%e so%e e*!%ples e*!%ples in e!"h e!"h "!te#ory. Answer. onsu%er #oods !re produ"ts pur"h!sed dire"tly by "onsu%ers, su"h !s "!rs, person!l "o%puters, 3s, tires, !nd tennis r!"-ets. !pit!l #oods !re those pur"h!sed by "o%p!nies to produ"e #oods !ndor !ndor provide servi"es. /*!%ples /*!%ples of "!pit!l #oods in"lude in"lude !ir"r!ft, "o%puters, "o%puters, "o%%uni"!tion e4uip%ent, %edi"!l !pp!r!tus, tru"-s !nd buses, r!ilro!d lo"o%otives, %!"hine tools, !nd "onstru"tion e4uip%ent.
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Wh!t is the differ differen"e en"e beteen beteen soft produ" produ"tt v!riety v!riety !nd h!rd h!rd produ"t produ"t v!riety v!riety,, !s these these ter%s !re !re defined in the te*t' Answer. Soft produ"t v!riety is hen there !re only s%!ll differen"es !%on# produ"ts, su"h !s the differen"es !%on# "!r %odels %!de on the s!%e produ"tion line. n !n !sse%bled produ"t, soft v!riety is "h!r!"teri6ed by ! hi#h proportion of "o%%on p!rts !%on# the %odels. 7!rd produ"t v!riety is hen the produ"ts differ subst!nti!lly, !nd there !re fe "o%%on p!rts, if !ny. he differen"e beteen ! "!r !nd ! tru"- e*e%plifies h!rd v!riety. v!riety.
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7o !re !re produ"t produ"t v!riety v!riety !nd produ" produ"tion tion 4u!nt 4u!ntity ity rel!te rel!ted d hen hen "o%p!rin# "o%p!rin# typi"!l typi"!l f!"tori f!"tories' es' v!riety. A f!"tory th!t Answer. Gener!lly produ"tion 4u!ntity is inversely rel!ted to produ"t v!riety. produ"es ! l!r#e v!riety v!riety of produ"ts ill ill produ"e ! s%!ller 4u!ntity 4u!ntity of e!"h. A "o%p!ny th!t produ"es ! sin#le produ"t produ"t ill produ"e ! l!r#e l!r#e 4u!ntity. 4u!ntity.
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:ne of the the di%ension di%ensionss of %!nuf!"tu %!nuf!"turin# rin# "!p!bi "!p!bility lity is is te"hnolo# te"hnolo#i"!l i"!l pro"ess pro"essin# in# "!p!bili "!p!bility ty.. &efine te"hnolo#i"!l pro"essin# "!p!bility.
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Solutions for Fundamentals of Modern Manufacturing , 5e (published by Wiley) MPGroover 2012
te"hnolo#i"!l !l pro"essin pro"essin# # "!p!bility "!p!bility of ! pl!nt pl!nt (or "o%p!ny) is its !v!il!ble !v!il!ble set of Answer. he te"hnolo#i" %!nuf!"turin# pro"esses. ert!in pl!nts perfor% %!"hinin# oper!tions, others roll steel billets into sheet sto"-, !nd others build !uto%obiles. he underlyin# fe!ture th!t distin#uishes these pl!nts is the pro"esses they "!n perfor%. e"hnolo#i"!l pro"essin# "!p!bility in"ludes not only the physi"!l pro"esses, but !lso the the e*pertise possessed possessed by pl!nt personnel in these pro"essin# te"hnolo#ies. te"hnolo#ies. 1.<
Wh!t !re the the four four "!te#o "!te#ories ries of en#ine en#ineerin# erin# %!teri!ls %!teri!ls used in %!nuf! %!nuf!"turi "turin#' n#' Answer. he four "!te#ories of en#ineerin# %!teri!ls !re (1) %et!ls, (2) "er!%i"s, () poly%ers, !nd () "o%posite %!teri!ls, hi"h "onsists of ! non;ho%o#eneous %i*ture of the other three types.
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Wh!t Wh!t is the the def defin init itio ion n of stee steel' l' defined !s !n iron>"!rbon iron>"!rbon !lloy "ont!inin# "ont!inin# 0.02 to 2.11 "!rbon. "!rbon. ts Answer. Steel "!n be defined "o%position often in"ludes other !lloyin# ele%ents !s ell, su"h !s %!n#!nese, "hro%iu%, ni"-el, !nd %olybdenu%, to enh!n"e the properties of the %et!l.
1.10 Wh!t !re so%e so%e of of the typi"!l typi"!l !ppli !ppli"!tio "!tions ns of steel' steel' Appli" i"!t !tio ions ns of stee steell in"l in"lud udee "ons "onstr tru" u"ti tion on (e.# (e.#., ., brid brid#e #es, s, ;be ;be!% !%s, s, !nd !nd n!il n!ils) s),, Answer. Appl tr!nsport!tion (tru"-s, r!ils, !nd rollin# sto"- for r!ilro!ds), !nd "onsu%er produ"ts (!uto%obiles !nd !ppli!n"es). 1.11 1.11 Wh!t is the differ differen"e en"e beteen beteen ! ther%opl!s ther%opl!sti" ti" poly%er poly%er !nd ! ther%osetti ther%osettin# n# poly%er' poly%er' Answer. her%opl!sti" poly%ers "!n be sub?e"ted to %ultiple he!tin# !nd "oolin# "y"les ithout subst!nti!lly !lterin# the %ole"ul!r stru"ture of the poly%er. poly%er. her%osettin# poly%ers "he%i"!lly tr!nsfor% ("ure) into ! ri#id stru"ture on "oolin# fro% ! he!ted pl!sti" "ondition.
1.12 M!nuf!"tur M!nuf!"turin# in# pro"esses pro"esses !re usu!lly usu!lly !""o%plis !""o%plished hed !s unit oper!tions oper!tions.. &efine unit oper!tio oper!tion. n. Answer. A unit oper!tion is ! sin#le step in the se4uen"e of steps re4uired to tr!nsfor% the st!rtin# %!teri!l into ! fin!l produ"t. A unit unit oper!tion is #ener!lly perfor%ed on ! sin#le pie"e of e4uip%ent th!t runs independently of other oper!tions in the pl!nt.
1.1 n %!nuf!"turin# %!nuf!"turin# pro"esses, pro"esses, h!t is the differen"e beteen ! pro"essin# oper!tion !nd !n !sse%bly oper!tion' pro"essin# oper!tion tr!nsfor%s ! or- %!teri!l fro% one st!te of "o%pletion to ! %ore Answer. A pro"essin# !dv!n"ed st!te th!t is "loser to the fin!l desired produ"t. t "h!n#es the #eo%etry, #eo%etry, properties, or !ppe!r!n"e of the st!rtin# %!teri!l. n #ener!l, pro"essin# oper!tions !re perfor%ed on dis"rete or- p!rts, but "ert!in pro"essin# oper!tions !re !lso !ppli"!ble to !sse%bled ite%s (e.#., p!intin# ! spot;elded "!r body). An !sse%bly oper!tion ?oins to or %ore "o%ponents to "re!te ! ne entity, "!lled !n !sse%bly, sub!sse%bly, or so%e other ter% th!t refers to the ?oinin# pro"ess (e.#., ! elded !sse%bly is "!lled ! eld%ent). 1.1 :ne of the three #ener!l types types of pro"essin# oper!tions is sh!pin# sh!pin# oper!tions, oper!tions, hi"h hi"h !re used to "re!te or !lter the #eo%etry of the or- p!rt. Wh!t !re the four "!te#ories of sh!pin# oper!tions' "!te#ories of sh!pin# sh!pin# oper!tions oper!tions !re (1) solidifi"!ti solidifi"!tion on pro"esses, pro"esses, in hi"h the Answer. he four "!te#ories st!rtin# %!teri!l is ! he!ted li4uid or se%ifluid th!t "ools !nd solidifies to for% the p!rt #eo%etry (2) p!rti"ul!te pro"essin#, in hi"h the st!rtin# %!teri!l is ! poder, !nd the poders !re for%ed !nd he!ted into the desired #eo%etry () defor%!tion pro"esses, in hi"h the st!rtin# %!teri!l is ! du"tile solid ("o%%only %et!l) th!t is defor%ed to sh!pe the p!rt !nd () %!teri!l re%ov!l pro"esses, in hi"h the st!rtin# %!teri!l is ! solid (du"tile or brittle), fro% hi"h %!teri!l is re%oved so th!t the resultin# p!rt h!s the desired #eo%etry. /*"erpts fro% this or- %!y be reprodu"ed by instru"tors for distribution on ! not;for;profit b!sis for testin# or instru"tion!l purposes only to reproduction or translation of this work work beyond that permitted students enrolled in "ourses for hi"h the te*tboo- h!s been !dopted. Any other reproduction by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful!
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Solutions for Fundamentals of Modern Manufacturing , 5e (published by Wiley) MPGroover 2012
1.15 Wh!t is the the differen"e differen"e beteen beteen net net sh!pe sh!pe pro"esses pro"esses !nd ne!r ne!r net sh!pe sh!pe pro"esses pro"esses'' Answer. @et sh!pe pro"esses !re %!nuf!"turin# pro"esses th!t tr!nsfor% ne!rly !ll of the st!rtin# %!teri!l into produ"t !nd re4uire no subse4uent %!"hinin# to !"hieve fin!l p!rt #eo%etry . @e!r net sh!pe pro"esses !re ones th!t re4uire %ini%u% %!"hinin# to produ"e the f in!l sh!pe.
1.18 dentify dentify the four four types of per%!nent per%!nent ?oinin# ?oinin# pro"esse pro"essess used in !sse%bly !sse%bly.. Answer. he four types !re eldin#, br!6in#, solderin#, !nd !dhesive bondin#.
1.19 1.19 Wh!t Wh!t is is ! %!" %!"hi hine ne tool tool'' Answer. he ter% developed durin# the ndustri!l evolution, hen it referred to poer;driven %!"hines used to oper!te "uttin# tools previously oper!ted by h!nd. Modern %!"hine tools !re des"ribed by the s!%e b!si" definition, e*"ept th!t the poer is ele"tri"!l r!ther th!n !ter or ste!%, !nd the level of pre"ision !nd !uto%!tion is %u"h #re!ter tod!y. tod!y.
1.1< Wh!t is the differen" differen"ee beteen spe"i!l spe"i!l purpose purpose !nd #ener!l #ener!l purpose purpose produ"tion produ"tion e4uip%ent' e4uip%ent' Answer. Gener!l;purpose e4uip%ent is %ore fle*ible !nd !d!pt!ble to ! v!riety of ?obs. t is "o%%er"i!lly !v!il!ble for !ny %!nuf!"turin# "o%p!ny to invest in. Spe"i!l;purpose e4uip%ent is usu!lly desi#ned to produ"e ! spe"ifi" p!rt or produ"t in very l!r#e 4u!ntities. Another re!son %!y be be"!use the pro"ess is uni4ue !nd "o%%er"i!l e4uip%ent e4uip%ent is not !v!il!ble. So%e "o%p!nies ith ith uni4ue pro"essin# re4uire%ents develop their on spe"i!l purpose e4uip%ent.
1.1= &efine &efine b!t"h produ"ti produ"tion on !nd des"ribe des"ribe hy it is often often used for %ediu%;4u %ediu%;4u!nti !ntity ty produ"tion produ"tion produ"ts. Answer. B!t"h produ"tion is here #roups, lots, or b!t"hes or %!teri!ls or p!rts !re pro"essed to#ether throu#h the %!nuf!"turin# oper!tions. All units in the b!t"h !re pro"essed !t ! #iven st!tion before the #roup pro"eeds to the ne*t st!tion. n ! %ediu% or lo 4u!ntity produ"tion situ!tion, the s!%e %!"hines !re used to produ"e %!ny types of produ"ts. Whenever ! %!"hine sit"hes fro% one produ"t to !nother, ! "h!n#eover o""urs. he "h!n#eover re4uires the %!"hine setup to be torn don !nd set up for the ne produ"t. B!t"h produ"tion !llos the "h!n#eover ti%e to be distributed !"ross ! l!r#er nu%ber of p!rts !nd hen"e redu"e the !ver!#e oper!tion ti%e per p!rt.
1.20 Wh!t is the differen"e differen"e beteen ! pro"ess l!yout l!yout !nd ! produ"t l!yout in ! produ"tion f!"ility' pro"ess l!yout is one here the %!"hinery in ! pl!nt is !rr!n#ed b!sed on the type of Answer. A pro"ess pro"ess it perfor%s. o o produ"e ! produ"t it %ust %ust visit the dep!rt%ents dep!rt%ents in the order of the oper!tions th!t %ust be perfor%ed. his often in"ludes l!r#e tr!vel dist!n"es ithin the pl!nt. A pro"ess l!yout is often often used hen the produ"t produ"t v!riety is l!r#e l!r#e the oper!tion se4uen"es se4uen"es of produ"ts !re dissi%il!r. dissi%il!r. A produ"t produ"t l!yout is one here the %!"hinery is !rr!n#ed b!sed on the #ener!l flo of the produ"ts th!t ill be produ"ed. r!vel dist!n"e is redu"ed be"!use produ"ts ill #ener!lly flo to the ne*t %!"hine in the se4uen"e. A produ"t l!yout or-s ell hen !ll produ"ts tend to follo the s!%e se4uen"e of produ"tion. 1.21 @!%e to dep!rt%en dep!rt%ents ts th!t !re typi"!lly typi"!lly "l!ssifie "l!ssified d !s %!nuf!"turin# %!nuf!"turin# suppor supportt dep!rt%ents. dep!rt%ents. f olloin# three %!nuf!"turin# support Answer. A "o%%on or#!ni6!tion!l stru"ture in"ludes the folloin# dep!rt%ents+ (1) %!nuf!"turin# en#ineerin#, (2) produ"tion pl!nnin# !nd "ontrol, !nd () 4u!lity "ontrol. 1.22 Wh!t !re overhe overhe!d !d "osts "osts in in ! %!nuf! %!nuf!"turi "turin# n# "o%p!ny "o%p!ny'' Answer. :verhe!d "osts "onsist of !ll of the e*penses of oper!tin# the "o%p!ny other th!n %!teri!l, l!bor, !nd e4uip%ent. /*"erpts fro% this or- %!y be reprodu"ed by instru"tors for distribution on ! not;for;profit b!sis for testin# or instru"tion!l purposes only to reproduction or translation of this work work beyond that permitted students enrolled in "ourses for hi"h the te*tboo- h!s been !dopted. Any other reproduction by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful!
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Solutions for Fundamentals of Modern Manufacturing , 5e (published by Wiley) MPGroover 2012
1.2 @!%e !nd define define the to "!te#or "!te#ories ies of overhe!d overhe!d "osts "osts in ! %!nuf!"turin# %!nuf!"turin# "o%p!ny "o%p!ny.. Answer. he to "!te#ories !re (1) f!"tory overhe!d !nd (2) "orpor!te overhe!d. C!"tory overhe!d "onsists of the "osts of runnin# the f!"tory e*"ludin# %!teri!ls, dire"t l!bor, !nd e4uip%ent. his overhe!d "!te#ory in"ludes pl!nt supervision, %!inten!n"e, %!inten!n"e, insur!n"e, he!t !nd li#ht, !nd so forth. orpor!te overhe!d "onsists of "o%p!ny e*penses not rel!ted to the f!"tory, su"h !s s!les, %!r-etin#, !""ountin#, le#!l, en#ineerin#, rese!r"h !nd develop%ent, offi"e sp!"e, utilities, !nd he!lth benefits.
1.2 Wh!t is the differ differen"e en"e beteen beteen fi*ed "osts "osts !nd !nd v!ri!ble v!ri!ble "osts' "osts' Answer. A fi*ed "ost re%!ins "onst!nt for !ny level of produ"tion output, here!s v!ri!ble "osts !re p!id for !s they !re used. he "ost of the f!"tory !nd e4uip%ent !re fi*ed "osts. &ire"t l!bor !nd %!teri!ls th!t !re used to produ"e the produ"t !re v!ri!ble "osts.
1.25 1.25 Wh!t Wh!t is %e!nt %e!nt by by the ter% ter% !v!i !v!il!b l!bil ility ity'' Answer. Av!il!bility is ! reli!bility ter% hi"h is si%ply the proportion upti%e of the e4uip%ent.
Problems Ansers to proble%s l!beled (A) !re listed in !n Appendi* Appendi* !t the b!"- of the boo-. Manufaturin! "onomis
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(A) A "o%p!ny invests D950,000 in ! pie"e of produ"tion e4uip%ent. he "ost to inst!ll the e4uip%ent in the pl!nt E D25,000. he !nti"ip!ted life of the %!"hine E 12 ye!rs. he %!"hine % !"hine ill be used ei#ht hours per shift, five shifts per ee-, 50 ee-s per ye!r. Appli"!ble overhe!d r!te E 1<. Assu%e !v!il!bility E 100. &eter%ine the e4uip%ent "ost r!te if (!) the pl!nt oper!tes one shift per d!y !nd (b) the pl!nt oper!tes three shifts per d!y.
E 50(1)(5)(<) E 2000 hryr. #olution+ (!) Cor ! one;shift oper!tion, hours of oper!tion per ye!r " E $sin# /4. (1.<), C e# e# E (950,000 F 25,000)(1.1<)(80 * 12 * 2000) E $%&'*min + $,&1%*-r (b) Cor ! three;shift oper!tion, hours of oper!tion per ye!r " E E 50()(5)(<) E 8000 hryr. E (950,000 F 25,000)(1.1<)(80 * 12 * 8000) E E $1.&/%*-r $%&.1.*min C e# e# @ote the si#nifi"!nt si#nifi"!nt !dv!nt!#e the "o%p!ny h!s h!s if it runs three shifts shifts per d!y r!ther th!n one shift. shift. 1.2
A produ" produ"tion tion %!"hin %!"hinee !s pur"h!se pur"h!sed d si* ye!rs ye!rs !#o for for !n inst!ll inst!lled ed pri"e pri"e of D50,000 D50,000.. At th!t th!t ti%e ti%e it !s !nti"ip!ted th!t the %!"hine ould l!st 10 ye!rs !nd be used 000 hours per ye!r. 7oever, it is no in need of %!?or rep!irs th!t ill "ost D125,000. f these rep!irs !re %!de, the %!"hine ill l!st four %ore ye!rs, oper!tin# 000 hours per ye!r. Appli"!ble overhe!d r!te E 0. Assu%e !v!il!bility E 100. &eter%ine the e4uip%ent "ost r!te for this %!"hine. #olution+ he "ost r!te under the ori#in!l "onditions !s the folloin#+ C e# e# E 50,000(1.0)(80 * 10 * 000) E D0.2<9%in E D19.2hr he rep!irs ill !dd to th!t "ost r!te !s follos+ C e# e# E 125,000(1.0)(80 * * 000) E D0.18=%in E D10.18hr he rep!ired %!"hine h!s ! "ost r!te C e# e# E 0.2<9 F 0.18= E $%&0'*min + $./&'*-r
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nste! nste!d d of rep!irin rep!irin# # the %!"hine %!"hine in Probl Proble% e% 1.2, 1.2, ! propos propos!l !l h!s been been %!de %!de to pur"h!s pur"h!see ! ne %!"hine !nd s"r!p the "urrent %!"hine !t ! 6ero s!lv!#e v!lue. he ne %!"hine ill h!ve ! produ"tion r!te th!t is 20 f!ster th!n the "urrent e4uip%ent, hose produ"tion r!te E 12 p!rts per hour. /!"h p!rt h!s ! st!rtin# %!teri!l "ost E D1. !nd ! sellin# pri"e E D8.0. All p!rts produ"ed durin# the ne*t four ye!rs on either %!"hine "!n be sold !t this pri"e. At the end of the four ye!rs, the "urrent %!"hine ill be s"r!pped, but the ne %!"hine ould still be produ"tive for !nother si* ye!rs. he ne %!"hine "osts D900,000 inst!lled, h!s !n !nti"ip!ted life of 10 ye!rs, !nd !n !ppli"!ble overhe!d r!te of 0. t ill be used 000 hours per ye!r, s!%e !s the "urrent %!"hine.
/*"erpts fro% this or- %!y be reprodu"ed by instru"tors for distribution on ! not;for;profit b!sis for testin# or instru"tion!l purposes only to reproduction or translation of this work work beyond that permitted students enrolled in "ourses for hi"h the te*tboo- h!s been !dopted. Any other reproduction by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful!
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Solutions for Fundamentals of Modern Manufacturing , 5e (published by Wiley) MPGroover 2012
he l!bor r!te for either !ltern!tive E D2.00hr hi"h in"ludes !ppli"!ble overhe!d "osts. Assu%e !v!il!bility E 100 !nd s"r!p r!te E 0. Whi"h !ltern!tive is %ore e"ono%i"!l usin# tot!l profit over four ye!rs !s the "riterion, (!) rep!irin# the "urrent %!"hine or (b) pur"h!sin# the ne %!"hine' #olution+ (!) he first !ltern!tive is to rep!ir the "urrent %!"hine. he "ost r!te !s deter%ined in the solution to Proble% 1.2. epe!tin# here, the ori#in!l "ost r!te is "!l"ul!ted !s follos+ C e# e# E 50,000(1.0)(80 * 10 * 000) E D0.2<9%in E D19.2hr he rep!irs ill !dd to th!t "ost r!te !s follos+ C e# e# E 125,000(1.0)(80 * * 000) E D0.18=%in E D10.18hr he rep!ired %!"hine h!s ! "ost r!te C e# e# E 0.2<9 F 0.18= E D0.58%in E D29.8hr !bor "ost E D2.00hr (#iven) Given th!t !nnu!l hours of oper!tion E 000, tot!l "ost of produ"tion on this %!"hine is "!l"ul!ted !s follos+ $C E E 000(2.00 F 29.8) E D205,0yr At ! produ"tion r!te of 12 p"hr !nd oper!tin# 000 hryr, !nnu!l output E 000(12) E <,000 p"yr ot!l revenue E <,000(8.0 > 1.) E D2,80yr. ot!l profit over four ye!rs E (2,80 > 205,0) E D151,8<0
(b) he se"ond %!"hine h!s !n e4uip%ent "ost r!te deter%ined !s follos+ C e# e# E 900,000(1.0)(80 * 10 * 000) E D0.9=%in E D22.95hr !bor "ost E D2.00hr (#iven) Given th!t !nnu!l hours of oper!tion E 000, tot!l !nnu!l "ost of produ"tion on this %!"hine is E 000(2.00 F 22.95) E D1<9,000yr $C E Produ"tion r!te on the ne %!"hine is 20 f!ster, so produ"tion r!te E 12(1.20) E 1. p"hr At 1. p"hr !nd oper!tin# 000 hryr, !nnu!l output E 000(1.) E 59,800 p"yr ot!l revenue E 59,800(8.0 > 1.) E D2=2,02yr. ot!l profit over four ye!rs E (2=2,02 > 1<9,000) E D20,12< on"lusion+ he ne %!"hine should be pur"h!sed !nd the old %!"hine s"r!pped. 1.
%!"hine tool is used to %!"hine p!rts in b!t"hes. n one b!t"h of interest, the st!rtin# pie"e is (A) A %!"hine ! "!stin# th!t "osts E D5.00 e!"h. B!t"h 4u!ntity E 0. he !"tu!l %!"hinin# ti%e in the oper!tion E 8.<8 %in. i%e to lo!d !nd unlo!d e!"h or-pie"e E 2.0 %in. ost of the "uttin# tool E D.00, !nd e!"h tool %ust be "h!n#ed every 10 pie"es. ool "h!n#e ti%e E 1.5 %in. Setup ti%e for the b!t"h E 1.95 hr. 7ourly !#e r!te of the oper!tor E D18.00hr, !nd the !ppli"!ble l!bor overhe!d r!te E 50. 7ourly e4uip%ent "ost r!te E D22.00hr, hi"h in"ludes overhe!d. Assu%e !v!il!bility E 100 !nd s"r!p r!te E 0. &eter%ine (!) the "y"le ti%e for the pie"e, (b) !ver!#e produ"tion r!te hen setup ti%e is fi#ured in, !nd (") "ost per pie"e. Pro"essin# # ti%e $ o E 8.<8 %in, p!rt h!ndlin# ti%e $ h E 2.00 %in, !nd tool h!ndlin# #olution+ (!) Pro"essin ti%e $ t t E E 1.50 %in10 E 0.15 %in. $ c E 8.<8 F 2.00 F 0.15 E &%1 min (b) Aver!#e Aver!#e produ"tion ti%e per pie"e in"ludin# setup ti%e $ p E 1.95(80)0 F =.01 E 11.8 %in 7ourly produ"tion r!te % p E 8011.8 E &1' 2*-r (") /4uip%ent "ost r!te C e# e# E D22.0080 E D0.89%in. !bor "ost r!te C & E 18.00(1.50) E D2.00hr E D0.0%in ost of toolin# C t t E E .0010 E D0.0p" Cin!lly, "ost per pie"e C pc E 5.00 F (0.0 F 0.89)(11.8) F 0.0 E $10&.*2
1.5 1.5
A pl!st pl!sti" i" %oldin %oldin# # %!"h %!"hin inee prod produ" u"es es ! prod produ" u"tt hos hosee !nnu !nnu!l !l de%!nd de%!nd is in the %ill %illio ions ns.. he he %!"hine is !uto%!ted !nd used full ti%e ?ust for the produ"tion of this produ"t. he %oldin# "y"le ti%e E 5 se". @o toolin# is re4uired other th!n the %old, hi"h "ost D100,000 !nd is e*pe"ted to produ"e 1,000,000 %oldin#s (produ"ts). he pl!sti" %oldin# "o%pound "osts D1.20lb. /!"h %oldin# ei#hs 0.<< lb. he only l!bor re4uired is for ! or-er to periodi"!lly retrieve the %oldin#s. !bor r!te of the or-er E D1<.00hr in"ludin# overhe!d. 7oever, the or-er !lso
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Solutions for Fundamentals of Modern Manufacturing , 5e (published by Wiley) MPGroover 2012
tends other %!"hines !nd only spends 20 of his ti%e on this %!"hine. Setup "!n be i#nored be"!use of the lon# produ"tion run. run. he %oldin# %!"hine !s pur"h!sed for for D500,000 inst!lled, its !nti"ip!ted life E 10 ye!rs, !nd it oper!tes 8000 hours per ye!r. /4uip%ent overhe!d r!te E 0. Assu%e !v!il!bility E 100 !nd s"r!p r!te E 0. &eter%ine (!) the hourly produ"tion r!te of the %!"hine, (b) !nnu!l 4u!ntity of produ"t %olded, !nd (") "ost per pie"e. #olution+ (!) With ! "y"le ti%e $ c E 5 se" E 0.95 %in, % p E 800.95 E <0 p"hr. C!"torin# in the =< proportion upti%e, % p E 0.=<(<0) E /,&0 2*-r Annu!l 4u!ntity of produ"t E 8000(9<.) E 0/%30%% 2*4r
(b) /4uip%ent "ost r!te C e# e# E 500,000(1.0)(80 * 10 * 8000) E D0.1<08%in. Mold "ost per pie"e C t t E E 100,0001,000,000 100,0001,000,000 E D0.10p" !bor "ost r!te C & E 1<.00(0.20) E D.80hr E D0.08%in Cin!lly, "ost per pie"e C pc E 1.20(0.<<) F (0.08 F 0.1<08)(0.95) F 0.10 E $1&0*2 1.8
A st!%p st!%pin# in# press press produ" produ"es es sheet; sheet;%et %et!l !l st!%pi st!%pin#s n#s in b!t"he b!t"hes. s. he press press is oper!te oper!ted d by ! or-er or-er hose l!bor r!te E D15.00hr !nd !ppli"!ble l!bor overhe!d r!te E 2. ost r!te of the press E D22.50hr !nd !ppli"!ble e4uip%ent overhe!d r!te E 20. n one ?ob of interest, b!t"h si6e E 00 st!%pin#s, !nd the ti%e to set up the die in the press t!-es 95 %in. he die "ost D0,000 !nd is e*pe"ted to l!st for 200,000 st!%pin#s. /!"h "y"le in the oper!tion, the st!rtin# bl!n-s of sheet %et!l !re %!nu!lly lo!ded into the press, hi"h t!-es 2 se". he !"tu!l press stro-e t!-es only < se". ost of the st!rtin# bl!n-s E D0.p". he press oper!tes 250 d!ys per ye!r, 9.5 hours per d!y, d!y, but the oper!tor is p!id for < hours per d!y. d!y. Assu%e !v!il!bility E 100 !nd s"r!p r!te E 0. &eter%ine (!) "y"le ti%e, (b) !ver!#e produ"tion r!te ith !nd ithout setup ti%e in"luded, !nd (") "ost per st!%pin# produ"ed. #olution+ (!) y"le ti%e $ c E 2 F < E 50 se" E %&, min
(b) n"ludin# setup ti%e, $ p E 9500 F 0.< E 1.021 %in % p E 801.021 E ,&/, 2*-r /*"ludin# setup ti%e, %c E 800.< E /.&% 2*-r (") /4uip%ent "ost r!te C e# e# E 22.50(1.20)80 E D0.5%in. &ie "ost per pie"e C t t E E 0,000200,000 E D0.20p" !bor "ost r!te C & E 15.00(1.2)80 E D0.55%in his l!bor "ost should be !d?usted for the f!"t th!t !lthou#h the press oper!tes 9.5 hrd!y, the oper!tor is p!id for < hr. hr. C & E 0.55(<9.5) E D0.9= Cin!lly, "ost per st!%pin# C pc E 0. F (0.9= F 0.5)(1.021) F 0.20 E $1&0,*2 1.9
A produ produ"ti "tion on %!"hine %!"hine oper! oper!tes tes in ! se%i;!u se%i;!uto to%!t %!ti" i" "y"le "y"le but ! or-er or-er %ust %ust tend the %!"hi %!"hine ne 100 of the ti%e to lo!d p!rts. $nlo!din# is !""o%plished !uto%!ti"!lly. he or-erHs "ost r!te E D29hr D29 hr in"lu in"ludin din# # !ppli" !ppli"!bl !blee l!bor l!bor overhe overhe!d !d r!te. r!te. he e4uip% e4uip%ent ent "ost "ost r!te r!te of the %!"hin %!"hinee E D1<.00hr in"ludin# !ppli"!ble overhe!d "osts. ost of the st!rtin# p!rts E D0.15p". he ?ob runs sever!l %onths so the effe"t of setup "!n be i#nored. /!"h "y"le, the !"tu!l pro"ess ti%e E 2 se", !nd ti%e to lo!d the p!rt E 8 se". Auto%!ti" unlo!din# t!-es se". A propos!l h!s been %!de to inst!ll !n !uto%!ti" p!rts;lo!din# devi"e on the %!"hine. he devi"e ould "ost D8,000 !nd ould redu"e the p!rt lo!din# ti%e to se" e!"h "y"le. ts e*pe"ted life E ye!rs. he devi"e ould !lso relieve the or-er fro% full;ti%e !ttention to the %!"hine. nste!d, the or-er "ould tend four %!"hines, effe"tively redu"in# the l!bor "ost to 25 of its "urrent r!te for e!"h %!"hine. he oper!tion runs 250 d!ys per ye!r, ei#ht hours per d!y. Assu%e !v!il!bility E 100 !nd s"r!p r!te E 0. &eter%ine the "ost per p!rt produ"ed (!) ithout the p!rts lo!din# devi"e !nd (b) ith the p!rts lo!din# devi"e inst!lled. (") 7o %!ny d!ys of produ"tion !re re4uired to p!y for the !uto%!ti" lo!din# devi"e' n other ords find the bre!-even point. #olution+ (!) /4uip%ent "ost r!te C e# e# E 1<80 E D0.0%in
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Solutions for Fundamentals of Modern Manufacturing , 5e (published by Wiley) MPGroover 2012
!bor "ost r!te C & E 2980 E D0.5%in Without the lo!din# devi"e, C pc E 0.15 F (0.5 F 0.0)(2 F 8 F )80 E $%&'*2 (b) ost r!te of the devi"e E 8,000(80 * * 2000) E D0.095%in E D.50hr With the lo!din# devi"e, C pc E 0.15 F (0.5 F 0.0 F 0.095)(2 F F )80 E $%&0*2 (") Without the devi"e, $ c E 2 F 8 F E se" E 0.55 %in !nd C pc E 0.58p" fro% p!rt (!) % p E %c E 800.55 E 10=.1 p"hr E <92 p"d!y With the devi"e, $ c E 2 F F E se" E 0.50 %in !nd C pc E 0.=p" fro% p!rt (b) At 100 reli!bility !nd no setup ti%e, % p E %c E 800.50 E 120.0 p"hr E =80 p"d!y et ' E nu%ber of d!ys of produ"tion !t hi"h the to !ltern!tives !re e4uiv!lent. <92(0.58) ' ' E 8,000 F =80(.=) ' ' =0.= ' E 8,000 F 9<.2 ' (=0.= > 9<.2) ' E 112.9 ' E 8,000 ' E 1=.5 round to .% 5a4s 1.<
(A) n ! lon#;runnin# hi#h;produ"tion oper!tion, the st!rtin# or- p!rt "ost E D0.=5 e!"h, !nd "y"le ti%e E 1.25 %in. /4uip%ent "ost r!te E D2<.00hr, !nd l!bor "ost r!te E D21.00hr. Both r!tes in"lude overhe!d "osts. oolin# oolin# "ost E D0.05p". Av!il!bility Av!il!bility of the produ"tion %!"hine E =8, !nd the s"r!p r!te E 9. &eter%ine (!) produ"tion r!te !nd (b) finished p!rt "ost. #olution+ (!) Produ"tion r!te, in"ludin# effe"t of !v!il!bility (801.25)(0.=8) E 8.0< p"hr 7oever, 7oever, be"!use of the 5 s"r!p r!te, the produ"tion r!te of !""ept!ble p!rts is % p E 8.0<(1;0.09) E 0.&, 2*-r
(b) C!"torin# in !v!il!bility !nd s"r!p r!te, p!rt "ost is C pc E 0.=50.= F ((21 F 2<)80)(1.25(0.= * 0.=8)) F 0.05 E $.&.1*2 1.=
he st!rt st!rtin# in# oror- p!rt "osts "osts D2.25 D2.25 in ! b!t"h b!t"h produ"t produ"tion ion oper! oper!tio tion. n. B!t"h B!t"h 4u!nti 4u!ntity ty E 100 p!rts. p!rts. /!"h "y"le, p!rt h!ndlin# ti%e E 0.50 %in, !nd oper!tion ti%e E 1.89 %in. Setup ti%e E 50 %in. /4uip%ent "ost r!te E D5.00hr, !nd l!bor "ost r!te E D1<.00hr, in"ludin# overhe!d "osts. here is no tool "h!n#e or tool "ost in the oper!tion. he %!"hine tool is 100 reli!ble, !nd s"r!p r!te E 5. &eter%ine (!) produ"tion r!te, (b) finished p!rt "ost, !nd (") nu%ber of hours re4uired to "o%plete the b!t"h. #olution+ (!) $ c E 1.89 F 0.50 E 2.19 %inp" Given # E 5, the st!rtin# 4u!ntity of p!rts (o E 1000.=5 E 105. rounded up to 108 p" &eter%ine b!t"h ti%e, in"ludin# setup ti%e. $ b E 50 F 108(2.19) E 50 F 20.02 E 2<0.02 %inb!t"h E .89 hr Aver!#e produ"tion r!te of p!rts % p E 100.89 E 21. p"hr Aver!#e produ"tion r!te of !""ept!ble p!rts % p E 21.(1 ; 0.05) E .%&' 2*-r
(b) @o deter%ine b!t"h "ost, in"ludin# setup ti%e. C b E 108(2.25) F ((1< F 5)(.89) E 2<.50 F 29.51 E D<8.01b!t"h C pc E <8.01100 E $0&,'*2 C pc+ Altern!tive "!l"ul!tion of C C pc E 2.250.=5 F ((1< F 5)80)(50100) F ((1< F 5)80)(2.190.=5) C pc E 2.8< F 0.2 F 2.01
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Solutions for Fundamentals of Modern Manufacturing , 5e (published by Wiley) MPGroover 2012
the %!"hine tool E =<, !nd the s"r!p r!te E . &eter%ine (!) produ"tion r!te !nd (b) finished p!rt "ost. (") 7o %!ny hours !re re4uired to "o%plete the the b!t"h' #olution+ (!) $ c E . F 2.5 F 15 E 8.1 %inp" Given # E , the st!rtin# 4u!ntity of p!rts (o E 850.=8 E 89.9 rounded up to 8< p" @o deter%ine b!t"h ti%e, in"ludin# setup ti%e !nd !v!il!bility, !v!il!bility, !ssu%in# th!t the !v!il!bility f!"tor does not !pply durin# setup be"!use the %!"hine is not runnin#. $ b E 95 F 8<(8.1)0.=< E 95 F 28.0 E 501.0 %inb!t"h E <.5 hr Aver!#e produ"tion r!te of p!rts % p E 85<.5 E 9.9< p"hr Aver!#e produ"tion r!te of !""ept!ble p!rts % p E 9.9<(1 ; 0.0) E /&0/. 2*-r
(b) @o deter%ine b!t"h "ost, in"ludin# setup ti%e !nd !v!il!bility, !ssu%in# th!t the !v!il!bility f!"tor does not !pply durin# setup be"!use the %!"hine is not runnin#. he nu%ber of "uttin# tools re4uired E 8<1< E .9< rounded up to tools !t D5.95 e!"h E D2.00. C batch batch E 8<(.50) F ((20 F 25)(<.5) F (5.95) E 2<.00 F 95.95 F 2.00 E D88.95b!t"h C pc E 88.9585 E $&/'*2 Altern!tive "!l"ul!tion of C C pc+ C pc E .500.=8 F ((20 F 25)80)(9585) F ((20 F 25)80)(8.1(0.=< * 0.=8)) F 2.0085 C pc E .88 F0.<85 F .<=5 F 0.5 E D=.980p" he differen"e fro% the previous v!lue of D=.9=8p" is due %ostly to the roundup of (o. (") he ti%e to "o%plete the b!t"h !s "o%puted in p!rt (!) !s $ b E %1&%0 min + ,& -r 1.11 (A) &urin# ! p!rti"ul!r 0;hour ee- of !n !uto%!ted produ"tion oper!tion, 8 !""ept!ble (non; defe"tive) p!rts !nd 22 defe"tive p!rts ere produ"ed. he oper!tion "y"le "onsists of ! pro"essin# ti%e of 5.9 %in, !nd ! p!rt h!ndlin# ti%e of 0.< %in. /very 80 p!rts, ! tool "h!n#e is perfor%ed, !nd this t!-es 9.2 %in. he %!"hine e*perien"ed sever!l bre!-dons durin# the ee-. &eter%ine (!) hourly produ"tion r!te of !""ept!ble p!rts, (b) s"r!p r!te, !nd (") !v!il!bility (proportion upti%e) of the %!"hine durin# this ee-. #olution+ (!) Produ"tion r!te of !""ept!ble p!rts % p E 50 E ,&0% 2*-r
(b) ot!l ot!l p!rts pro"essed durin# the ee- (o E 8 F 22 E 5< p" S"r!p r!te # E 225< E 0.0815 E '&16 (") y"le ti%e of the unit oper!tion $ c E 5.9 F 0.< F 9.280 E 8.2 %in ot!l upti%e durin# the ee- E 5<(8.2) E 220. %in E 9.19 hr Proportion upti%e A E 9.190 E 0.=2= E .&6 1.12 A hi#h;pro hi#h;produ"t du"tion ion oper!tio oper!tion n !s studied studied durin# durin# !n <0;hr period. period. &urin# th!t th!t ti%e, ! tot!l of seven seven e4uip%ent bre!-dons o""urred for ! tot!l lost produ"tion ti%e of .< hr, !nd the oper!tion produ"ed < defe"tive produ"ts. @o setups ere perfor%ed durin# the period. he oper!tion "y"le "onsists "onsists of ! pro"essin# pro"essin# ti%e of 2.1 %in, ! p!rt h!ndlin# h!ndlin# ti%e of 0.85 %in, !nd ! tool "h!n#e "h!n#e is re4uired every 25 p!rts, hi"h t!-es 1.50 %in. &eter%ine (!) hourly produ"tion r!te of !""ept!ble p!rts !nd (b) s"r!p r!te durin# durin# the period. #olution+ (!) y"le ti%e of the unit oper!tion $ c E 2.1 F 0.85 F 1.5025 E 2.<5 %in 7ours of produ"tion durin# <0 hours E <0 > .< E 98.2 hr ot!l nu%ber of p!rts produ"ed E 98.2(80)2.<5 E 180 p" @u%ber of !""ept!ble p!rts produ"ed produ"ed E 180 > < E 1588 1588 p" Produ"tion r!te of !""ept!ble p!rts % p E 1588<0 E 1&, 2*-r
(b) S"r!p r!te # E <1588 E 0.02 E .&06
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