Bài giảng nhập môn quản lý xây dựng

PUBLIC WORKS ECONOMICS Department of Construction Management - Faculty of Economic and Management A bottling company installed a conveyor system 10 years ago at the cost of $20,000 The company is considering replacing the system because maintenance costs have been increasing and new technology is available that will be less costly to operate and provide greater performance You have been assigned to analyze both systems and recommend the most economical decision – retain the old system or replace it with the new system A petroleum company needs to paint the vessels and pipes in its refinery periodically to prevent rust “ • Tuff-Coat, a durable paint, can be purchased for $8.05 a gallon • Quick-Cover, a less durable paint, costs $3.25 a gallon Both paints are equally easy to apply and will cover the same area per gallon Quick-Cover is expected to last years How long must TuffCoat last to justify its use? You are the city engineer for a small but growing community and are applying for a grant to help fund an upgrade to the wastewater treatment plant The new design is based on population growth over the next 20 years The grant requires • Multiple design alternatives be evaluated • An economic justification • A 7% “discount rate” You and your spouse have just had a beautiful baby boy You want to start saving for his college education now Given the rising costs of college, how much should you save each month to ensure you will have enough to fund his education in 18 years? You have found your dream home, but you need to decide how to finance the purchase Should you obtain a • 30-year fixed rate mortgage? • 15-year fixed rate mortgage? • A creative financing option that your uncle is offering that requires you pay no interest for the first years of the loan? You have saved $20,000 in your 401K Should you withdraw that money and use it as a down payment or keep it invested? Course Objectives • Be able to prepare economic justifications for engineering proposals • Be able to manage personal finances and make wise investment decisions Course Objectives (cont.) • Be able to evaluate economic justifications performed by others • Be comfortable using financial language • Be aware of tradeoffs involving expenses and capital costs under tax and inflation conditions • Be familiar with advanced techniques of modeling decision problems under risk and uncertainty conditions What is Engineering Economic Analysis? • Definition: applying economic analysis techniques to compare alternative engineering projects • Other names – Engineering economy – Economic decision analysis – Capital investment analysis • Cash flow analysis $ $ +$ -$ Engineering Economic Analysis • Engineers must – understand how money works in order to make informed design decisions – make decisions over the entire product life cycle (cradle to) – consider the economics of the design in order to “sell” it to management / public • Determine if a project is “economically viable” grave • Choose the “best” project between multiple alternatives Norm of advance calculated taxable income(%) No Type of works Civil works Industrial works Transport works Irrigation works Technical infrastructure works The installation contact of technological equipment in the construction works and construction, installation of line, the experiment, calibration of power lines and substation, the testing of Advance calculated taxable income 5,5 6 5,5 5,5 49 Norm of Temporary worker accommodation and site office costs (%) Direct costs (billion VND) No Type of works [1] [2] ≤ 15 ≤100 ≤500 ≤1000 >1000 [3] [4] [5] [6] [7] Works under the route 2,3 2,2 2,0 1,9 1,8 Other works 1,2 1,1 1,0 0,95 0,9 50 Norm of Costs related to unspecified workloads (%) No Type of works Rate (%) Civil works Industrial works Transport works Irrigation works 25 Technical infrastructure works 2,0 2,0 2,0 2,0 51 Synthesis of estimate of construction costs calculated by incomplete work construction unit price and incomplete general construction price No Content of costs Calculation method I Direct costs VL+NC+M Cost of materials 𝑛 𝑄𝑗 𝑥 𝐷𝑗 𝑣𝑙 Signs T VL 𝑗=1 Labor cost 𝑛 𝑄𝑗 𝑥 𝐷𝑗 𝑛𝑐 NC 𝑗=1 Cost of construction machines 𝑛 𝑄𝑗 𝑥 𝐷𝑗 𝑚𝑡𝑐 M 𝑗=1 II Indirect costs C + LT + TT + GTk GT General costs T x rate C Temporary worker accommodation and site office costs T x rate Costs related to unspecified workloads T x rate TT Other indirect costs Estimation GTk III Advance calculated taxable income (T+GT) x rate TL (T+GT+TL) G VAT G x TGTGT-XD GTGT After-tax construction cost G + GTGT 𝐺𝑥𝑑 Before-tax construction cost IV LT Synthesis of estimate of construction costs calculated by complete work construction unit price and complete general construction price No Cost items Before-tax construction cost VAT After-tax construction cost Calculation method n Q i 1 i x Di G x T GTGT  XD G+GTGT Value Signs G GTGT GXD 53 3.2 Determination of equipment costs GTB GTB  GMS  GDT  GLD In particular: GMS : the cost of purchasing technological equipment GDT : the cost of training and technology transfer GLD : the cost of equipment installation, testing, and calibration 54 Cost of purchasing technological equipment n GMS   Qi M i i 1 In particular: Qi : the volume or the number of i thequipment : price per a unit of volume or a unit of the th i number of equipment, is determined by the formula Mi M i  Gg  Cvc  Clk  Cbq  T 55 Gg : equipment price at the purchase place or the price calculated to Vietnam port (for imported equipment) has included the cost of design and fabrication supervision Cvc : transportation cost per a unit of volume or a unit of the number of equipment from the place of purchase or from the port of Vietnam to the work Clk : costs of storing warehouse, wharf, containers per a unit volume or a unit of the number of equipment in Vietnam’s ports for imported equipment Cbq : the cost of preservation and maintenance per a unit volume or a unit of the number of equipment in site T : taxes and fees of insurance, inspection of equipment 56 Cost of purchasing technological equipment • The costs of training and technology transfer are calculated by making cost estimate or advance calculation, depending on the specific characteristics of each project • Costs of equipment installation, testing, and calibration are estimated as to the construction cost 57 3.3 Determination of the project management cost GQLDA  T x (GXDtt  GTBtt ) T: the ration norm (%) for project management cost GXDtt pre-tax construction cost GTBtt pre-tax the equipment cost 58 3.4 Determination of the cost of construction investment consultancy GTV n m i 1 j 1 GTV   Ci   Di In particular Ci : the j th cost of construction investment consultancy based on the ratio norm D j : the i th cost of construction investment consultancy calculated by making cost estimation 59 3.5 Determination of other costs GK n m l i 1 j 1 k 1 GK   Ci   D j  CHMC   Ek C i : i th other costs calculated by the ratio norm j th D j : other costs calculated by making cost estimate Ek : k th concerned other costs CHMC : Cost of general items 60 3.5 Determination of other costs GK CHMC  (CNT  CKKL ) x(1  T)  C K C NT : cost of temporary housing on site for dwelling and construction administration CNT is calculated by the rate of 2% on the construction cost and cost of equipment installation, testing, calibration before VAT for the works by routes such as the electricity transmission lines, postal communication lines, traffic roads, canals, pipelines, other line forms construction works and equal to 1% for the remaining works 61 3.5 Determination of other costs GK CKKL : Cost of other works in the general items but unable to be determined from the design such as costs for moving the workforce within the construction site, occupational safety, environmental protection for laborers and surrounding environment, materials testing of the contractor and the irregular costs of pumping, dredging sludge CK : Other cost of general items T: Value Added Tax 62 3.6 Determination of reserve costs GDP GDP  GDP1  GDP GDP1 reserve cost for arising workload element is determined by the formula: GDP1  (GXD  GTB  GQLDA  GTV  G K )x K ps K ps is a reserve coefficient for the volume of arising workload K ps  5% GDP reserve cost for the drift of price is determined as for reserve cost for the drift of price in the total investment 63