1、Designation: F 1675 09An American National StandardStandard Practice forLife-Cycle Cost Analysis of Plastic Pipe Used for Culverts,Storm Sewers, and Other Buried Conduits1This standard is issued under the fixed designation F 1675; the number immediately following the designation indicates the year o
2、foriginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice establishes a procedure for using life cycl
3、ecost (LCC) analysis techniques to evaluate alternative drainagesystem designs, using plastic pipe that satisfy the samefunctional requirements.1.2 The LCC technique measures the present value of allrelevant costs to install, operate, and maintain alternativedrainage systems such as engineering, con
4、struction, mainte-nance, rehabilitation, or replacement over a specified period oftime. The practice also accommodates any remaining residualor salvage value.1.3 The decision maker, using the results of the LCCanalysis, can then identify the alternative(s) with the lowestestimated total cost based o
5、n the present value of all costs.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitat
6、ions prior to use.2. Referenced Documents2.1 Other Standards:TM-5-802-1 Economic Studies for Military ConstructionDesign Applications (12/86)2Federal Office of Management and Budget Guidelines andDiscount Rates for Benefit-Cost Analysis of FederalPrograms and state documents for guidelines or requir
7、e-ments3ASTM Adjuncts:Discount Factor Tables43. Terminology3.1 Definitions:3.1.1 common costs, ncosts that are common to allalternatives in nature and amount, such as initial planning feesor future annual inspection costs.3.1.2 discount rate, nthe investors time value of money,expressed as a percent
8、, used to convert costs occurring atdifferent times, to equivalent costs at a common point in time.3.1.3 drainage project, na project having a definable,functional drainage requirement that can be satisfied by two ormore design or construction alternatives, or both.3.1.4 future costs, ncosts require
9、d to keep the systemoperating that are incurred after the project is placed in service,such as operation, maintenance, rehabilitation, or replacementcosts.3.1.5 inflation, nthe general trend or rising prices that,over time, result in the reduction of the purchasing power ofthe dollar from year to ye
10、ar.3.1.6 initial cost, nthe total of all costs; such as designcosts, material purchase costs, and construction/installationcosts, that are specific to each alternative and are incurred tobring each alternative to a point of functional readiness.3.1.7 maintenance cost, nthe annual or periodic costs,s
11、uch as inspection and cleaning to keep a drainage structurefunctioning for the project design life, but do not extend thematerial service life.3.1.8 material service life, nthe number of years ofservice a particular material, system, or structure will providebefore rehabilitation or replacement is n
12、ecessary.3.1.9 project design life, nthe planning horizon for theproject, expressed as the number of years of useful life requiredof the drainage structure.3.1.10 rehabilitation cost, nthe total of all costs incurredto extend the material service life of a specific alternative.3.1.11 replacement cos
13、t, nthe total of all costs incurred toreplace a material before the end of the project design life.3.1.12 terminal value, nthe remaining value of the drain-age structure in place at the end of the project design life.1This practice is under the jurisdiction of ASTM Committee F17 on PlasticPiping Sys
14、tems and is the direct responsibility of Subcommittee F17.62 on Sewer.Current edition approved Aug. 1, 2009. Published August 2009. Originallyapproved in 1996. Last previous edition approved in 2003 as F167503.2Available from Headquarters, Department of the Army, Washington, DC.3Available from Offic
15、e of Management and Budget, Washington, DC.4Available from ASTM International Headquarters. Order Adjunct No.ADJE091703.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States
16、.4. Summary of Practice4.1 This practice outlines a procedure for conducting anLCC analysis of two or more drainage pipe alternatives usingplastic pipe over a specified project design life. This practiceidentifies the project data and general assumptions needed forthe analysis and the method of comp
17、utation.5. Significance and Use5.1 LCC analysis is an economic method to evaluate alter-natives that are characterized by differing cash flows over thedesignated project design life. The method entails calculatingthe LCC of each alternative capable of satisfying the functionalrequirements of the pro
18、ject and comparing them to determinewhich have the lowest estimated LCC over the project designlife.5.2 The LCC method is particularly suitable for determiningwhether the higher initial cost of an alternative is economicallyjustified by reductions in future costs (for example, operatingmaintenance,
19、rehabilitation, or replacement) when compared toan alternative with lower initial costs but higher future costs. Ifa design alternative has both a lower initial cost and lowerfuture costs than other alternatives, an LCC analysis is notnecessary to show the former is the economically preferablechoice
20、.6. Procedure6.1 The procedure for performing an LCC analysis fordrainage pipe applications is as follows:6.1.1 Identify project objectives, alternatives, and con-straints (6.2).6.1.2 Establish basic assumptions (6.3).6.1.3 Compile data (6.4).6.1.4 Compute life cycle cost for each alternative (7.1).
21、6.1.5 Evaluate results (7.2).6.2 Project Objectives, Alternatives, and Constraints:6.2.1 Specify the design objective that is to be accom-plished, identify alternative systems or designs that accomplishthat objective, and identify any constraints that may limit theoptions to be considered.6.2.2 An e
22、xample is the design of a storm water drainagesystem for a residential development project. The system mustsatisfy mandated drainage system objectives, such as specifiedrainfall intensities and storm water runoff limits. Availablealternatives, such as different pipe materials and varyingconfiguratio
23、ns of catch basins, ponds, or underground deten-tion chambers may have different initial costs as well asexpected future costs. The system design may be constrainedby structural and hydraulic limits such as minimum andmaximum slopes and depth of burial, limits on surface flows onstreets, etc.6.3 Bas
24、ic Assumptions:6.3.1 Establish the uniform assumptions to be made in theLCC analysis of all alternatives. These assumptions include theselection of the discount rate, the treatment of inflation, generalinflation rate, the project design life, and the desired compre-hensiveness of the analysis.6.3.2
25、Discount RateThe discount rate selected shouldreflect the owners time value of money. That is, the discountrate should reflect the rate of interest that makes the ownerindifferent between paying or receiving a dollar now or at somefuture time. The discount rate is used to convert costs occurringat d
26、ifferent times to equivalent costs at a common point in time.6.3.2.1 There is no single correct discount rate for allowners. Selection of the discount rate should be guided by therate of return on alternative investment opportunities of com-parable risk (that is, the opportunity cost of capital), or
27、, in thecase of some public organizations, on mandated or legislatedfederal or state requirements. (See Federal Office of Manage-ment and Budget.)6.3.2.2 The discount rate may include general price inflationover the study period. This discount rate is referred to as the“nominal” discount rate in thi
28、s practice. The discount rate mayalso be expressed as the real earning power of money over andabove general price inflation, referred to as the “real” discountrate.6.3.2.3 A nominal discount rate (dn) and the correspondingreal discount rate ( dr) are related as follows:dr51 1 dn1 1 I2 1ordn5 1 1 dr!
29、 1 1 I! 2 1 (1)where:I = the rate of general price inflation.6.3.2.4 The same discount rate should be used in evaluatingeach design alternative. Annex A1 contains a procedure tofollow in developing the discount rate. This procedure may beapplied by those who wish to select their own values as well a
30、sthose who are required to follow mandated or legislatedrequirements.6.3.3 InflationThis practice is designed only to accommo-date a uniform rate of general inflation. Calculate the LCC inconstant dollar terms (not including general inflation) or incurrent dollar terms (including general inflation).
31、 If the latter isused, a consistent projection of general price inflation shall beused throughout the LCC analysis, including adjustment of thediscount rate to incorporate general inflation (6.3.2.2). Thepercentage change in GNP deflator and the Producers PriceIndex are two broad indicators of gener
32、al inflation.6.3.3.1 If the user desires or is required to treat inflation onan incremental (differential) basis, or uniquely to each indi-vidual cost component (for example, energy costs), consulteither TM-5-802-1 or Discount Factor Tables4, respectively.6.3.4 Project Design LifeEstablish the proje
33、ct design life(3.1.9) from mandated public policy, legislated requirements,or selection by the owner based on situation requirements. Usethe same design life for each alternative under comparison andfor all categories of cost under consideration. The potential forfuture obsolescence, that is, the po
34、tential that future changesmay modify drainage system requirements, should be consid-ered in selecting project design life.6.3.5 ComprehensivenessThe appropriate degree of pre-cision and detail to use in an LCC analysis is dependent uponthe intended use of the analysis. A less comprehensive ordetail
35、ed analysis may be sufficient to roughly rank manyalternatives, whereas a more comprehensive analysis may benecessary to select from among a few close alternatives. In anycase, omitting significant factors from an LCC analysis dimin-ishes the usefulness of the results.F 1675 0926.3.6 Sensitivity Ana
36、lysisNo analysis is more precise thanthe accuracy of the data and assumptions used in the calcula-tion. When there is uncertainty regarding basic assumptions(for example, cost estimates, design life, discount rate, etc.)calculate the LCC for a range of assumptions. The results ofthese calculations w
37、ill show the user the extent to which theresults are sensitive to variations of the key assumptions.6.4 Compiling DataCompile the data specific to eachalternative under consideration.6.4.1 Initial CostsThe estimated dollar amount of allcosts is required to bring the alternative system to a point off
38、unctional readiness.6.4.2 Material Service LifeMaterial service life is thenumber of years of service expected of the alternative understudy, which varies depending upon the pipe material, theenvironment, effluent, and application. Potential changes inenvironmental conditions which may affect the ma
39、terial servicelife should be considered. Use job site tests, published reports,manufacturer product data, and local experience to establishservice life for each material. If material service life is less thanthe project design life (3.1.9), the analysis shall include thefuture cost to sufficiently e
40、xtend the service life throughrehabilitation or replacement, in order to at least equal theproject design life.6.4.3 Future CostsCost estimates should be made for allsignificant items that are estimated to be required to allow thedrainage system to satisfy performance requirements over theproject de
41、sign life. Common costs (1.1) may be excludedwithout affecting the relative ranking of the alternatives understudy. The cost estimates should be made in constant dollars(not including inflation) in the same time frame as the estimateof initial costs.6.4.3.1 Operating CostOperating cost is an estimat
42、e ofthe annual cost for labor, power, and consumable materials andsupplies required to operate a drainage system. Except forpumped systems, most drainage systems do not have signifi-cant annual operating costs.6.4.3.2 Maintenance CostMaintenance cost includes costestimates and the frequency of any i
43、nspection, cleaning, andminor repair necessary to keep the system operating at capacityduring the project design life.6.4.3.3 Rehabilitation CostRehabilitation cost is the costof major repairs to extend the material service life to equal orexceed the project design life. If more than one rehabilitat
44、ion isanticipated, the years in which the rehabilitation are plannedshould be noted.6.4.3.4 Replacement CostReplacement cost is the timingand cost estimate for complete replacement of any drainagesystem component. Take care to see if the service life of thereplaced material or component will at leas
45、t equal the remain-ing project design life. If not, rehabilitation or further replace-ment will be necessary.6.4.3.5 Terminal ValueTerminal value is the value of thedrainage system at the end of the project design life. Thepotential residual or salvage value of a drainage system isdependent upon som
46、e of the factors considered in establishingproject design life. For example, if a storm sewer is beingevaluated and a long project design life (75 years) is used,consideration should be given to risk of future obsolescence. Ifthe likelihood of functional obsolescence is high, then theremay be no res
47、idual or salvage value. If, however, it is expectedthe material could be removed and either reused or sold, thenthe net cash value (in constant dollars) represents the terminalvalue. It is not recommended to use a residual value to reflectan economic value for any remaining material life in excess o
48、fthe project design life. As an alternative, if the functionalrequirements of the system under design are for an indefiniteperiod, then consideration should be given to increasing theproject design life to an appropriately higher value, where theresidual value would not significantly affect the comp
49、arison ofthe various alternatives.7. Calculations7.1 Computing Life Cycle CostsTo compute the LCC fora drainage system, all relevant cost flows over the design life ofthe project are discounted back to the present and summed.7.1.1 Find the present value (PV) of each cost category forexample, initial cost (IC), operating and maintenance (M),rehabilitation or repair (R) and terminal value ( T) using theappropriate discount formula in this section. Then sum thesepresent values to find PVLCC, for example,PVLCC 5 PVIC 1 PVM 1 PVR 2 PVT (2)7.1.2 Initial costs
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