CNM
KHOA HOC KINH TC V/k QUAN LY N G A N H MOTRAO DOI VE VIEC VAN DUNG SO DO PERT TRONG CONG TAC QUAN TRj CHI PHJ CUA DOANH NGHIEP
CN. TRUNG PHUONG Vign KHCN Md-Vlnacomin
V
do ndm 1957, phuang phap dudng thdi gian Thdi gian dy kiln=(Tli uu+4XChdc chdn+Bi quan)/6 tdi hgn (hay cdn gpi Id dudng •'gdng")-CPM Dk tinh todn phuang sai cho thdi gian hoan (Critical Path Method) dd dugc t h i hiOn dudi thdnh, nlu lya chpn ta lin thdi gian lOch chuIn cho cac dgng md hinh mgng su- dgng trong viOc quan ly dy thdi gian tii inj vd thdi gian tii quan thi se cd sdu lech chuIn dn. CPM Id phuang phdp tit djnh SLP dgng phdp giu-a chung, vittil, phuang sai sedipgc tinh ttieo:udc tinh thdi gian I n djnh cho tirng cdng viOc. Phuang sai a^= [(Bi quan-Toi uu)/6]^
Phuang _^phdp ndy d l hiiu, de SLP dgng, tuy nhiOn vdi viOc vdn dgng phdn phii p nen udc luong khdng d l cdp den cdc biln thdi gian, anh hudng thdi gian hodn thdnh cdng viOc khd chinh xdc,'rat din thdi gian hodn thdnh dy dn. phu hgp trong viOc t l chu'c thi cdng, nhat Id doi vai
Khdc vdi phuang phdp CPM, phuang phdp PERT nhCrng trudng hgp cdng vipc chua ed djnh mCrc.
(Program Evaluation and Review Technique) cd nghTa Thyc t l nhilu cdng trinh xdy dyng dd t l chirc Id kT thudt udc lugng vd kilm tra dy dn, cho phdp ddnh thi cdng theo PERT vd dgt dugc cdc kit qua kha gid ngdu nhien thdi gian hodn thdnh mOt hogt dOng. quan, giam thilu dugc nhQ'ng tdc hai do dilu kien Thyc te cdc phuang phdp sa do mgng (CPM) vd thi cOng khOng thudn Igi, dam bao tiln dO thi cong.
PERT dugc phdt trien gin nhu ddng thai, cd nhilu Qud trinh khdc phuc khd khdn trong thi cdng, vdi diem tuang ding v l nOi dung nen PERT van dugc coi mgc tieu rut ngdn "dudng gdng thi cdng" cung la nhu mOt phuang phdp sa do mgng. Tuy^nhidn, cho dOng lyc trong vipc hodn thiOn cdng nghp, dOi mai den nay, trong cdc phuang phdp sa do mgng thi trang, thilt bj, phdt huy sdng kiln cai tiln ky thuat, phuang phdp PERT dugc nhilu ngudi bilt din han dii mdi t l chCre san xult. Tuy nhien, d ddy chung ca, md ddu In ldn nhdt dd Id ndm 1958 d My ngudi ta tdi muln ndi den viec vdn dgng phuang phdp nay SLP dgng PERT de t l chu-e thi cdrig xdy dyng hO thing trong ITnh vyc quan trj chi phi, khi dd, trong sa d6 ten lu-a Polaris, nhd dd dd mt ngdn thdi gian xdy dyng PERT thay bdng "dudng gdng thi cdng" se la so vdi to chCpc thi eOng theo cdc phuang phdp CPM "dudng gdng chi phi" Tuy nhien, khde vdi "dudng khdc tu- 5 ndm xudng cdn 3 ndm. Sau cdng trinh ndy g§ng thi cdng" Id ting thdi gian thi cOng cdc hang PERT dugc phi biln rlt nhanh sang cdc linh vyc khdc mgc cdng trinh khdng t h i t l chCre thi cdng song trong nen kinh t l quIc ddn d My. song cdn "dudng gdng chi phi" Id ting cdc chi phi
Doi vdi phuang phdp CPM thi sa d l mgng Id cua tirng cdng dogn trong ddy chuyin san xudt.
mpt mO hinh xdc djnh, xem thdi hgn hodn thdnh Vi dg trong mOt md khai thdc than him 10, day moi cOng vipc Id khOng dii (t=const), tuy nhi§n chuyin san xult vdi cdc cdng dogn san xudt chinh trong thyc te thi cdng thudng gdp rlt nhilu ylu t l bao gIm: (1) khai thdc than trong Id cha; (2) van tai ngau nhien nhu tdc dOng v l thdi tilt, viOc cung d p than trong Id; (3) ddo Id chudn bi san xudt; (4) thong nguyen, vgt lipu, thiet bj,... Vi vdy. thdi hgn hodn gid; (5) thodt nudc; (6) vgn tai ngodi mdt bdng (d^n thdnh cdc cdng vipc nhilu khi khdng e l djnh (t=tij). kho than hode nhd sdng); (7) sdng, tuyin than; v.v...
tu- dd phuang phdp PERT dd dua vdo ylu t l mli mOt cdng dogn tuang Crng Id ehi phi thuc hien, khOng xdc djnh (ylu t l nglu nhien) vdi viOc vdn ting hgp Id chi phi san x u l t Khi dO dudng gdng chi dgng If thuyet xdc suit thing kg vd logi phdn phii phi se bao gIm cdc dogn nii tilp nhau vd dugc thi xdc suit thudng su- dgng Id phdn phii p khi udc hiOn (mang tinh gia djnh) tren hinh dudi day, trong do lugng thdi gian thyc hipn cdc cdng viOc vd thdi dogn (1-2) Id chi phi khai thdc than Id chg: 160.000 gian hodn thdnh dy dn. Theo dd, khoang thdi d/tin; dogn (2-3) Id chi phi van tai than trong 16:
gian dy kiln cho mdi hogt dOng cd t h i tinh gin 60.000 d/tan;... dogn (7-8) Id chi phi sdng tuyin, chi dung bdng trung binh cd trpng s l sau: biln than: 20.000 d/tIn;....
C O N G NGHIEP MO S 0 1 2012
KHOA HOC KINH TE VA QUAN LY NGANH MO
CNM
1 V- <2 AZ h-m ' (5 i-(6)-(7)—(8
H. 1. "Dudng gang chi phi" (gid djnh) cua mdt ddy chuyen san xuit trong md khai thdc than him Id.
Cdn phai ndi them, ehi phi d l xdy dyng "dudng gang" ndy Id ehi phi thyc t l , trong dilu kipn eg t h i tip cOng nghp dp dung, dan gid, djnh mire, d i n trang, thilt bj, con ngudi vd md hinh td chCpc san xult. TCP
"dudng gang chi phi" nay trudc tien Nhd quan ly phai xdc djnh xem ed t h i giam dugc chi phi khdng? muln vdy, phai lap sa dd PERT "chi phi", xdc djnh cdc chi phi lien quan d i n tirng "cdng dogn" chi phi, moi quan he giQ'a chung, tu' dd, xdc dinh cac trudng hgp chi phi nho nhdt (tii uu), chi phi kha thi (chdc chdn) vd chi phi ldn nhdt (bi quan). Tip nhQ-ng k i t qua nay cd t h i xdc djnh dugc chi phi dy kiln cho tipng cdng dogn san xudt eua ddy chuyin:
Chi phi dy kiln=(Tdi uu+4XChde chdn+Bi quan)/6 Tip chi phi dy k i l n cua tipng cdng dogn, so sdnh vdi chi phi thyc t l tren "dudng gdng" se xdc djnh dugc trong dilu kipn eg t h i tai thdi d i l m ndy cdng dogn ndo cd t h i giam chi phi.
Gia SLP sau khi so sdnh thdy dogn (1-2) tuang irng Id chi phi khai thdc than Id chg ed dO Ipch chi phi ldn nhit, t i l p dd Id dogn (2-3), v.v... vd trong kha nang gidi hgn, trudc tien, Nhd quan ly tdp trung vdo giam chi phi cdng dogn (1-2) Id cdng dogn khai thdc than Id chg, m u l n vdy phai tra Idi cdu hoi giam bdng cdch ndo? Dk tra Idi cdu hdi ndy, mOt ldn nQ'a Nhd quan ly Igi phai quay Igi sa dO PERT "ehi phi" d l rd sodt cdc ehi phi lien quan d i n khoan chi phi ndy, nhu sau:
• COng nghp khai thdc dp dung dd hodn thipn chua, d n b l sung hogc thay t h i trang, thilt bj nhdm ndng cao ndng lye eua cdng nghp?
• T l chu'c san x u l t da hgp ly chua, ndng s u i t lao dOng d mu-c dO ndo vd cO t h i hodn thien khdu ndy nhu t h i ndo?
• Djnh mCpc tieu hao vdt tu, nhien lieu, dipn, nudc dd hgp ly chua, cdn lang phf a khdu ndo?....
Tu- dO, Nhd quan ly se dua ra giai phdp t i n g t h i d l giam chi phf cOng dogn nay vd sau dd, cung vdi each thCpc tuang ty, t i l p tgc giam chi phi cdng dogn (2-3), (3-4), vd ... cho d i n h i t cdc cdng dogn tren todn bO ddy chuyin san xult, Idm giam gid thdnh san phdm, cO t h i coi nhu dd hodn thdnh mOt chu trinh d i i mdi.
Tuy nhien, sau khoang thdi gian hodn thdnh mOt chu trinh thi cung trong thdi gian dd, nhd cdc tac dOng hiru ca, nhQ'ng d i i mdi da Idm chi phi cua cdc cOng dogn Igi ldn, vi dg do d i i mdi d cOng dogn van tai da Idm tdng ndng s u i t khai thdc than 10 chg,... vd cOng dogn (1-2) Igi trd thdnh d i i tugng dk giam chi phf, vd khi dd Igi b i t d I u mOt
chu trinh giam chi phi mdi. CCP ldp Igi nhu vdy, nhu
"vOng xody trilt hpc" chi phi san xudt se giam dan tuang Cpng vdi trinh dO vdn hdnh cOng nghe, trinh dO t l ehCpc san xult, ndng suit lao dOng, ... ndng len theo dung quy ludt quan hp "lugng-chat"
Cung phai ndi them, cgm tip "giam chi phi" d day phai hiiu theo nghTa rOng, dd Id khdng tinh d i n cdc tdc dOng tdng chi phi mang y l u t l xd hOi nhu muc luang ca ban tdng, trugt gid,... Nhu vdy, trong nhQ-ng trudng hgp ndy, n l u giam mire dO tdng chi phi dugc coi Id giam chi phi.
Vdi xu t h i hipn nay, trinh dO cQng nhu kiln thCpc cua cdc Nhd quan ly doanh nghipp ngay cdng dugc nang cao, hodn todn cd the van dung dugc sa do PERT trong cdng tac quan tri ehi phi eua doanh nghipp, vd vdi vipc van dung nay khong nhQ'ng gdp p h i n quan tri chi phi, ndng cao hieu qua san xuat kinh doanh, gdp phdn tipng bude ndng cao ndng s u i t lao dOng xd hOi, md quan trpng han, giCip cho Nhd quan ly ddn giam bdt cam tfnh, mang tinh ly tri nhilu han, khdch quan han trong cdng tdc quan tri doanh nghipp.D
Nguoi bien tgp: Dao Dae Tgo
SUMMARY
The paper introduces some opinions of using the PERT scheme in the management for expenses in the mining enterprises. .
QUAN LY TAI NGUYEN..
(Tiep theo trang 40)
Nghj djnh hudng dan thi hdnh Lugt khodng san d n dugc sdm ban hdnh eg t h i hda vipc phdn chia cdc logi tdi nguyen khodng san khu vyc khdng ddu gid quyln khai thdc md khodng san (nhd nudc quan ly d p phep); khu vyc d I u gid quyln khai thdc md vd khu vyc k§u ggi v i n dau t u nudc ngodi; dam bao cd sy d i n g bO giu'a thi hdnh Lugt khodng san vd Ludt Doanh nghiOp, d i n g thdi d l Ludt sdm di vdo cuOc slng.(!!I
Nguoi bien tgp: Ho ST Giao
SUMMARY
Paper introduces some solutions of resources management and permission for mineral activities for sustainable development.
C 0 N G N G H | £ P MO S 0 1 - 2 0 1 2
