總裝車間SPS運(yùn)行方式分析

1、總裝車間sps運(yùn)行方式分析圖1  總裝車間平面布置 隨著豐田生產(chǎn)方式在汽車行業(yè)的引入，總裝車間物流的sps（set parts system）配貨方式也在中國(guó)得到了極大關(guān)注，無(wú)論是豐田合資、大眾合資還是通用合資都在大力推廣應(yīng)用。sps配貨方式就是按每車裝配輛份配送貨物的方式。本文將重點(diǎn)分析sps配貨方式的優(yōu)勢(shì)、適用條件以及如何合理有效地應(yīng)用。sps運(yùn)行方式現(xiàn)以總裝車間為例，說(shuō)明sps運(yùn)行方式。 圖1是年生產(chǎn)單班5000輛整車的總裝車間平面布置圖。整車裝配在一環(huán)形線上完成一次內(nèi)飾、底盤裝配和二次內(nèi)飾裝配，全線有26個(gè)裝配工位（圖1中藍(lán)線所示區(qū)域）。sps區(qū)域分三塊（圖1中粉色線所示區(qū)域

2、），即儀表板分裝零件配貨區(qū)、底盤零件配貨區(qū)和一次內(nèi)飾及二次內(nèi)飾零件配貨區(qū)。 總裝車間廠房?jī)?nèi)僅為中小零件的配貨區(qū)，大件零部件配貨、零部件的拆箱、開捆及大件零部件的分裝均在另一廠房?jī)?nèi)，即物流倉(cāng)庫(kù)（見(jiàn)圖2）。圖2  物流倉(cāng)庫(kù)平面布置1.配貨順序總裝車間的物流系統(tǒng)在信息控制系統(tǒng)指導(dǎo)下，有條不紊地從倉(cāng)庫(kù)貨架取出所需零件，按sps配貨方式送到指定工位，配貨順序如下：（1）中央控制室（ccr）根據(jù)市場(chǎng)分析及訂單情況安排生產(chǎn)計(jì)劃，并將生產(chǎn)計(jì)劃的車輛順序信息向總裝車間情報(bào)中心傳遞。（2）車輛順序信息傳到總裝車間情報(bào)中心，由情報(bào)信息員根據(jù)實(shí)際工位查找相應(yīng)信息指示卡。（3）情報(bào)信息員將信息指示卡投遞到sp

3、s供應(yīng)管理板處。（4）物流配貨人員從sps供給管理板處獲取信息選取配貨指示票，配貨指示票上標(biāo)有某個(gè)車型在某個(gè)工程裝配零件的種類和數(shù)量。（5）物流人員按照配貨指示票到sps區(qū)配貨（kittting），放在相應(yīng)的臺(tái)車上，物流人員將部品放到運(yùn)輸臺(tái)車上。（6）配完后放在供給待發(fā)區(qū)，物流人員將零件供給到生產(chǎn)線的起始位置。（更先進(jìn)的方式是agv自動(dòng)輸送至相應(yīng)工位。（7）物流人員將空臺(tái)車返回到零件供給待發(fā)區(qū)，通過(guò)sps方式配貨完成。2. 物料配送的四個(gè)步驟在圖3的sps物料及信息流程圖中我們可以看到，所有的物料都是經(jīng)過(guò)四個(gè)步驟完成運(yùn)送的：接收物料需求信息（圖3中）；按需求信息進(jìn)行配貨（圖3中）；將配貨送到裝

4、配線的接收端（圖3中）；隨裝配線完成裝配工序（圖3中）。sps運(yùn)行方式的優(yōu)勢(shì)1.上線點(diǎn)減少一輛份零件被分成有限的幾部份，分別在幾個(gè)上線點(diǎn)與整車隨行。上線點(diǎn)的減少意味著在線旁的物流線路變得簡(jiǎn)單、清晰了。簡(jiǎn)單的物流線路意味著交叉點(diǎn)的減少、沖突點(diǎn)的降低。圖3  sps物料及信息流程圖2.線旁物料面積減少由于整車所需裝配的零件均按輛份與車身隨行，線旁的物料面積就不需要了。以往由于生產(chǎn)綱領(lǐng)提高所造成的線旁物料面積的矛盾也就不存在了。3.通道面積可能削減如果能夠整線實(shí)現(xiàn)sps配貨方式，sps配貨的上線點(diǎn)均設(shè)在線的端部，那么在整線中部工位沒(méi)有物料需求，通道也就可以削減或取消了。4.防錯(cuò)功能裝配線上

5、操作工人的工作內(nèi)容由原來(lái)的挑撿零件和裝配零件兩道工序變?yōu)橹挥醒b配零件，而且由于所裝配零件有明顯差異，操作工人不會(huì)出現(xiàn)錯(cuò)裝；由于每個(gè)隨行的料架均是按輛份配送的，所以如果裝配后料架上有剩余零件，則為漏裝，操作工人可及時(shí)發(fā)現(xiàn)和糾正錯(cuò)誤。5.減輕操作工人的勞動(dòng)強(qiáng)度操作工人不需要去線邊的料架去取零件。由于料架是隨行的，操作工人可以就近取件，減少了操作工人頻繁走動(dòng)所增加的勞動(dòng)強(qiáng)度。6.提高了勞動(dòng)生產(chǎn)率由于操作工人減少了取件及挑撿零件的用時(shí)，減少了每個(gè)裝配零件所需的工時(shí)，使得整線提高節(jié)拍成為可能。sps運(yùn)行方式的局限1.節(jié)省面積問(wèn)題無(wú)庸置疑，在sps配貨方式中，最大限度地節(jié)省了裝配線旁的物料面積，但是它增加

6、了配貨面積，這部分面積是采用傳統(tǒng)送貨方式時(shí)所不需要的。從整個(gè)車間角度上看，總面積沒(méi)有節(jié)省反倒是增加了。以前面所提廠項(xiàng)為例，16000m2的總面積中，裝配車間生產(chǎn)面積為4880 m2，物流配貨面積為7186 m2，通道面積為2926 m2，其他輔助面積為1008 m2。從上面的數(shù)據(jù)可以看出物流配貨面積約是裝配生產(chǎn)面積的1.47倍（不包括通道面積）。在另兩個(gè)豐田廠項(xiàng)中，一個(gè)廠總裝車間裝配生產(chǎn)面積約為13600 m2，而物流面積達(dá)到24600 m2，裝配與物流面積之比約為1 : 1.8；另一個(gè)廠總裝車間裝配生產(chǎn)面積約為41000 m2，而物流面積達(dá)61200 m2，裝配與物流面積之比約為1 : 1.

7、49。而我們以往采用送貨制生產(chǎn)方式時(shí)，設(shè)計(jì)的裝配生產(chǎn)面積與物流面積之比是按1 : （0.60.8）考慮的。物流面積是非生產(chǎn)面積，是不創(chuàng)造價(jià)值的面積。物流面積的增加大大地增加了新廠建設(shè)投資和生產(chǎn)廠的場(chǎng)地占用成本，實(shí)際上最終增加了產(chǎn)品的成本。這與豐田的精益思想是相悖的。2.防錯(cuò)功能問(wèn)題這里的防錯(cuò)功能包括兩個(gè)方面，一方面是防裝錯(cuò)，即防止差異較小的零件裝錯(cuò)車；另一方面是防漏裝。在同一條生產(chǎn)線上生產(chǎn)的車型，既使是多品種，也都是一個(gè)系列的車型，也就是說(shuō)，在同一條生產(chǎn)線上生產(chǎn)的車型中的大部分零件及總成件都是一樣的。為了少量差異零件的防錯(cuò)裝而把所有零件都放在料車上，從成本和操作難度上綜合考慮，是否必要，值得我

8、們探究。3.配送零件質(zhì)量保證問(wèn)題由于配送零件是按輛份送到每個(gè)車旁的，也就是說(shuō)沒(méi)有備份，當(dāng)裝配過(guò)程中出現(xiàn)質(zhì)量問(wèn)題（如零件不合格、損壞或遺失）時(shí)，由于沒(méi)有備份零件，沒(méi)有線旁的物料供給，那么這輛車只能隨其他車一起下線，再到返修區(qū)進(jìn)行裝配了。這樣大大就增加了返修區(qū)的工作量，增加了返修面積。因此，sps運(yùn)行方式對(duì)入庫(kù)零件質(zhì)量要求非常高，要求配送的零件合格率為100，并且保證在運(yùn)送過(guò)程中，無(wú)質(zhì)量事故。這對(duì)于同種零件成批送貨相對(duì)容易保證，而對(duì)于按輛份配送的方式，由于要將結(jié)構(gòu)各異的零件都放在同一配送小車上，保證起來(lái)會(huì)有一定的困難。4.提高生產(chǎn)效率問(wèn)題這個(gè)問(wèn)題應(yīng)該從兩個(gè)方面討論：一個(gè)方面是零件搬運(yùn)問(wèn)題。sps運(yùn)

9、行方式造成了零件的“二次搬運(yùn)”，將零件取出送到配送區(qū)，再?gòu)呐渌蛥^(qū)取出零件放到隨行料架上，比傳統(tǒng)的送貨方式增加了一次零件配送，是屬于豐田生產(chǎn)方式所說(shuō)的“7種浪費(fèi)”之一，可見(jiàn)其是影響生產(chǎn)效率的。 另一個(gè)方面是人在裝配過(guò)程中的取件用時(shí)問(wèn)題。sps運(yùn)行方式一直強(qiáng)調(diào)操作工人從隨行料架上取件比線旁取件所走的距離短。事實(shí)上，筆者在實(shí)行sps運(yùn)行方式的總裝車間看到的是隨行料架放在兩工位之間，操作工人到隨行料架取件至少要走出1m遠(yuǎn)，與到線邊料架相比并不近。因此，通過(guò)隨行料架取件和到線旁料架取件對(duì)工人裝配效率的影響區(qū)別是微乎其微的。5.sps運(yùn)行方式適用的零件問(wèn)題sps運(yùn)行方式是將整車零部件按輛份放在隨行料架上，

10、但我們很難想象大型總成件，如保險(xiǎn)杠、座椅和輪胎等也放在隨行料架上，這些零件會(huì)使隨行料架變得很大；另外還有一些有分裝內(nèi)容的總成件，如儀表板、車門、動(dòng)力總成和風(fēng)擋玻璃等也不會(huì)采用隨行料架送到裝配工位的。由此可見(jiàn)，sps運(yùn)行方式適用的是中小型的零件，如成套鎖、門把手和內(nèi)護(hù)板等件。sps的適用條件sps運(yùn)行方式最大的優(yōu)勢(shì)體現(xiàn)在不同種類車型的差異件的取用和判斷上，最大限度地減少了操作工人的判斷失誤。sps運(yùn)行方式并不適用于大批量的整車生產(chǎn)方式。sps運(yùn)行方式更適用的是批量小、品種多且差異件多的整車試制線，或一些零件比較小，而零件在運(yùn)送過(guò)程中不易受到損傷的總成件分裝。toyotas new materia

11、l-handling system shows tpss flexibility toyota motor corporation has introduced a new material-handling system based on kitting to reduce complexity and improve quality in assembly areas.the new approach was introduced in japan and china, according to art smalley, author of the lean enterprise inst

12、itute workbook creating level pull. smalley saw the new system in action on an engine assembly line during a recent tour of toyota facilities in japan. he was one of the first americans to work for toyota in japan in the 1980s and helped transfer toyotas equipment and lean manufacturing methods over

13、seas.a spokesman for toyota motor north america said the kitting system was being introduced on “more and more lines” at the georgetown facility and elsewhere in north america. he said it was “not a complete sea change” in parts presentation and wasnt applicable to all production areas. smalley said

14、 the system, called the set pallet system (sps) in japan, appeared best suited to automated lines, rather than cells. the new approach removed line-side storage racks, often called flow racks, so operators no longer walked from their assembly stations to get parts. instead, electronic signals told m

15、aterial handlers what parts to select from bins separate from the line. they then selected and placed the parts on pallets traveling with the engines being assembled (see diagrams below   “visually, its quite a difference because the flow racks are gone,” said smalley. “i was surprised. it

16、 was a much more open and clear area than the traditional scenario with all the material around the line, which can block you from seeing. the line is so wide open now.”more value-added workat georgetown, the correct parts for a particular camry or avalon are selected into a tray that is placed insi

17、de the car as it heads down the line. because part selection is done upstream, assemblers can “focus on the quality of installation,” according to the toyota spokesman. variety and the resulting complexity have proliferated as more and more features are offered to customers. for instance, before the

18、 new system was introduced for the current generation camry and avalon, team members had to choose between 24 varieties of sun visors.the change means operators now focus nearly 100% of their time on the value-added work of installing parts because they no longer have to perform the nonvalue-adding

19、task of walking a few steps to retrieve parts from flow racks, smalley noted. “operators stay in a very tight zone, doing almost 100% value-added time.”the switch also eliminates reaching, stretching, and searching for parts by assembly operators. the new arrangement also makes training operators an

20、d material handlers easier because the job responsibilities are narrower.the new system concentrates walking and parts selection on the material handlers who are positioned every seven to 10 stations along the engine assembly line, smalley said. although the new system increased the number of materi

21、al handlers, he commented that, on average, toyota estimated that the total productivity change was neutral due to the more effective use of direct labor. a minor drawback to the new approach was that it made adding or subtracting pickers incrementally as takt time changed somewhat harder to do.

22、0; advantages and disadvantagesthe big advantage of the new material handling system is simplicity and quality improvement through error avoidance. smalley explained that toyota japan had about 5% seasonal or temporary workers when he was there in the 1980s. “now the figure is up to 40% in some

23、 plants,” he said. “also the work force is younger than it was 20 years ago and labor law changes allow for more women to work in assembly.” all these trends create a workforce that is less experienced with factory work and less familiar with automotive components than in the past. combined with the

24、 proliferation of component variety, part selection errors were occurring and small quality problems, like assembly errors and bolts not being sufficiently torqued, were getting downstream. “i guess they just couldnt poka-yoke everything and the logical step was to simplify further,” he said. the ne

25、w system was introduced at a vehicle assembly plant in china co-owned by toyota that had limited space for storing material at the final assembly the line, smalley said. a kaizen effort produced the sps approach. “other managers saw it and loved the effect it had on clearing up the area around the l

26、ine,” he said. “the line became less cluttered, easier to see, easier to walk around, and just felt like a much more open work space. one by one the vehicle plants switched over during the past year or two and now the engine assembly lines are doing the same.” although the system is considered new,

27、smalley points out that there was a similar version being used at line number 14 in toyotas kamigo engine plant about 20 years ago. the line supplier nearly 100 different types of engines and thousands of minor variations at the part number level used on the engine worldwide. other lines did not suffer the same complexity issues and the system thus never spread. smalley noted that adoption of the sps material handling system today demonstrates that tps flexibly adapts to the needs of the situation rather than forcing a so