S dng Bng AQL [AQL]Kha hc 1: Cc kin thc c bn v qun l cht lngCho b phn QACp nht ngy 05 thng 4 nm 2013
Quy trnh bi ging
Cc bc trong quy trnhHot ngThi gian d kin
Gii thiuNgi hng dn gii thiu5 pht
Phn 1:K hoch ly mu v nh ngha AQLHng dn bng slideThc hnh60 pht
Phn 2:ng dng Bng AQLHng dn bng slideThc hnh60 pht
Kim tra k nngKim tra k nng25 pht
Phng php kim hangVic nh gi cc c tnh v cht lng c thc hin theo mt s cc phng php. C 6 phng php c lit k di y l c s dng mt cch rng ri. Khng kim Kim 100% Ly mu theo % nht nh Kim lng hng ngu nhin Ly mu kim [Tiu chun c th chp nhn v loi] Ly mu c th chp nhn da vo xc sut1. Khng kim tra c th c m bo khi bit c kh nng v xc sut sn phm li l nh. Trong mt s trng hp, cc nguyn liu n t cc nh cung cp khc nhau c th khng c kim tra bi v nh cung cp c cc tnh nng ni tri v cht lng.Khi khng bit kh nng v mc cht lng ca sn phm, khng kim tra thng dn n hu qu l cc chi ph tng v phi ti ch cc sn phm li. Khi cc sn phm li v tnh b giao hng cho cc n v tip theo s dng, theo cc cng on phi b dng li sa. Khi bit c cc ri ro c th xy ra, phng php ny c th dn n cc tn tht v rc ri ng k cho cng ty.2. Mt khc, sn phm c th c kim 100%. Trong trng hp c th, kim 100% hoc thm ch kim 200% c th cn thit, c bit khi n lin quan n vic sng cn. Trong cc quy trnh hng ngy, kim tra tng sn phm l rt tn km chi ph v thng khng t hiu qu 100% v khng cn thit m bo cht lng. Cch kim 100% l mt cch phn loi sn phm tt khi sn phm li.3. Phng php ly mu khng khoa hc, l phng php ly mu theo % nht nh, y l mt quy trnh rt ph bin. Ti sao khng lm mi chuyn n gin v ch ly 10% mu t mt l hng? Vn ca phng php ny l mu ly t cc l hng nh c th qu t v mu ly t l hng ln c th qu ln. ng thi, cc ri ro km theo chng ta khng th lng trc c. Mt im na l, mt mu ln khng cha ng nhiu thng tin. Nu s lng mu l ng k quyt nh mc cht lng v c th a ra quyt inh chp nhn hay loi l hng , vic ly mu nhiu hn s khng cn thit.4. Kim lng hng ngu nhin i khi c s dng khi mun kim sot thng k mt quy trnh no . Kim tra ngu nhin c s dng kim tra quy trnh ang trong qu trnh kim sot v bo co mc cht lng ca sn phm. Khng bit c ri ro ca vic ly mu, cng nh phng php ny khng m bo c cht lng u ra c mc c th chp nhn c hay khng. Loi ly mu ny c th c s dng khi mt nh cung cp c cp chng ch hoc c chng nhn l lun cung cp mt sn phm c cht lng tt nht trong mt thi gian di hoc kh nng kim l kh tt nn cc phng php kim tra khc l khng cn thit.5. Ly mu kim l vic ly mu c thc hin da theo cc cch c bn thng gp nhng tiu chun chp nhn khng c th. Mt bn bo co cht lng c to v cc n v sn xut s quyt nh s phi lm g nu sn phm khng th chp nhn. S dng phng php ly mu kim khi cc bin php kim sot cht lng sn xut c bit l c thc hin mt cch chnh xc. Kh nng tin hnh phi c bit v xc sut ca cc hng li theo mc kim tra phi rt nh.6. Ly mu chp nhn, da vo xc sut, n c s dng hu khp trong ngnh cng nghip may. Nhiu phng php ly mu c dng thnh bng v c pht hnh v c th c s dng trong cc bui o to nh. Mt s cc ng dng yu cu cc phng php ly mu c bit duy nht, v th chng ta c th hiu c phng php ly mu c pht trin nh th no l rt quan trng. Trong ly mu chp nhn, ta bit c ri ro ca vic a ra mt quyt nh sai. Khi kim hng c nh gi bi thi , [sn phm c phn loi theo t cht lng v li] s dng 4 kiu phng php ly mu chp nhn, vi cc phng php ly mu tng l hng mt l ph bin nht. l bi v chng d thc hin v tin hnh hn so vi nhng phng php khc v chng c hiu qu.
Tt c chng ta bit rng kim tra l cng c c s dng nh gi sn phm ca chng ta c p ng c cc thng s k thut v cc yu cu ca khch hng ra hay khng? Mc d kim tra l quan trng v n cho chng ta bit mc c th chp nhn c ca mt sn phm nhng n khng th a ra xc xut kim l 100% cho tt c s lng ca mt n hng c th hoc ca nhiu n hng. Ch yu l do cc nguyn nhn sau: Tn km chi ph. Kim 100% him khi t c chnh xc 100% v c th tin cy c. N c th khng c tnh thc t v vic x l s lng hng ha qu ln dn n kt qu l hng ha mt i tnh mi ca n.
Chng ta bit rng kim 100% c th khng l mt cch lm tt nht, cu hi ra l Nu khng kim tra 100% th chng ta phi kim bao nhiu? C 2 s la chn. La chn th nht l t ra mt t l kim c nh ca cc l hng s c kim t c mt mc c th chp nhn c ca ton b l hng. Hoc la chn th hai l s dng quy trnh Ly mu chp nhn t c mt phng php ly mu theo bng AQL cho v a ra mt quyt nh chp nhn. La chn u tin l ty v n khng c tnh khoa hc v mt c bn m c th cho chng ta bit mc ng tin cy ca phng php kim ny. Bi v cc quyt nh chp nhn l cc quyt nh mang tnh kinh t quan trng nn vic c mt phng php ng tin v c tnh khoa hc a ra quyt nh chp nhn nh vy l rt quan trng v phng php ny c th trnh c ri ro.Ly mu chp nhn l mt phng php khoa hc v n cng cho chng ta thy c xc sut ca vic a ra s nh gi sai khi s dng phng php ny.
K hoch ly muK hoch ly mu l g? Cc cch kim tra trn mt sn phm, c yu cu kim tra da trn 2 tiu ch: chp nhn hay l loi Mt mu c la chn v c kim tra da trn nhiu yu t khc nhau. Quyt nh da trn cc tiu ch c th v s lng li hoc loi li c pht hin trn mu kim. Sn phm: c nhm theo cc l hng hoc tng chic n l t mt chui ni tip. Vi cc sn phm c nhm theo l hng, chp nhn hoc loi ton b l hng . Vi sn xut lin tc, c th a ra quyt nh tip tc ly mu hoc kim tra 100% cc sn phm tip theo.Ly mu khi kt thc quy trnh sn xut l tin hnh kim tra d cc quy trnh kim sot cht lng c c thc hin hay khng. Nu cht lng c kim sot mt cch tt, sn phm s c chp nhn v c chuyn n cho cc n v tip theo hoc n tay khch hng. Nu cht cht lng hoc kim sot cht lng khng tt, quy trnh ly mu s ngn c s lng cc sn phm li khng qu ln. B phn sn xut cng c th s dng phng php ly mu ny.
T chc kim tra hoc chc nng kim tra cui chuyn c nhng mc tiu sau nhm t c qua vic p dng cc phng php ly mu. m bo cht lng nhng khng ci thin cht lng Bo co thc trng cht lng ca b phn sn xut cho nhng ngi qun l Cung cp cc bin php an ton thch hp ngn vic vn chuyn cc sn phm li m bo rng cc b phn sn xut thc hin ng chc nng ca mnh trong vic kim sot cht lng
Vi phng php ly mu, c hai dng:Ly mu n v ly mu kp.Mt s khch hng c th yu cu ly mu n v mt s c th yu cu ly mu kp, tt c u ph thuc vo yu cu ca khch hng.V c bn chng ta bit c iu g? Nhng khchh ng khc nhau s c nhng tiu chun cht lng khc nhau.
Ly mu nKhi mt l hng c chuyn n kim tra cht lng hoc v tr kim tra, chng ta la chn mt lng mu kim ngu nhin t l hng .Nu s lng li hoc s o li trong mu vt qu s o li c th chp nhn c, l hng s b loi [khng t].Nu s lng li hoc s o li trong mu khng vt qu s o li c th chp nhn c, l hng c chp nhn [t].Cc l hng khng t thng c ch thch chi tit cc nguyn nhn b loi. Trong mt s trng hp c th b loi.V cc l hng t v chp nhn c gi ti tay khch hng. Nhng l hng khng t s c tr li kim tra li.Ly mu kpMt l hng c chuyn n kim tra cht lng hoc v tr kim tra.Gi s hai lng mu kim l n1, n2 v hai s lng c th chp nhn c l c1, c2 hoc AN1, AN2].u tin, ly lng mu kim n1.Nu s lng cc li hoc s s li trong mu kim u tin vt qu c2, l hng khng t v mu kim th hai khng cn phi kim.Nu s o li trong mu kim u tin khng vt qu c1, l hng t v mu kim th hai khng cn phi kim na.Nu s o li trong mu kim u tin ln hn c1 v nh hn hoc bng c2, mu kim th hai [n2] s phi ly kim tra.Nu mu kim th hai c kim:a] v c s o li cng vi s o li ca mu kim th nht khng vt qu c2, l hng c nh gi l T.b] v c s o li cng vi s o li ca mu kim th nht vt qu c2, l hng c nh gi l KHNG Ti] L hng khng t c ch thch r rng hoc b loi.ii] L hng t v chi tit l hng khng t c gi ti cng giao hngV d v ly mu kp:Nu s o liKt qu
Mu kim th nht: n1>c2L hng khng t, khng cn kim mu kim th hai
c1