1、Designation: A 930 03Standard Practice forLife-Cycle Cost Analysis of Corrugated Metal Pipe Used forCulverts, Storm Sewers, and Other Buried Conduits1This standard is issued under the fixed designation A 930; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers a procedure for using life-cycle cost(LCC) analysis techn
3、iques to evaluate alternative drainagesystem designs using corrugated metal pipe that satisfies thesame functional requirements.1.2 The LCC technique measures the present value of allrelevant costs of installing, operating, and maintaining alterna-tive drainage systems, such as engineering, construc
4、tion, main-tenance, rehabilitation, or replacement, over a specified periodof time. The practice also accommodates any remainingresidual or salvage value.1.3 Using the results of the LCC analysis, the decisionmaker can then identify the alternative(s) with the lowestestimated total cost based on the
5、 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 limitations
6、prior to use.2. Referenced Documents2.1 ASTM Standards:E 917 Practice for Measuring Life-Cycle Costs of Buildingsand Building Systems22.2 Other Documents:TM-5-802-1 Economic Studies for Military ConstructionDesignApplications (12/86)Circular No. A-94 Guidelines and Discount Rates forBenefit-Cost Ana
7、lysis of Federal Programs33. Terminology3.1 Definitions:3.1.1 common costs, ncosts common to all alternatives innature and amounts such as initial planning fees or futureannual inspection costs.3.1.2 discount rate, nthe investors time value of money,expressed as a percent, used to convert the costs
8、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.3.1.4 future costs, ncosts required to keep the systemoperating that
9、 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 thatresult in reduction of the purchasing power of the dollar fromyear to year over time.3.1.6 initial cost, nthe total of all
10、 costs, such as designcosts, material purchase costs, and construction and 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,such as inspection and cleaning, to k
11、eep a drainage structurefunctioning for the project design life but that do not extend thematerial service life.3.1.8 material service life, n the number of years ofservice that a particular material, system, or structure willprovide before rehabilitation or replacement is necessary.3.1.9 project de
12、sign 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 cost, nthe total of all cost
13、s incurred toreplace a material before the end of the project design life.3.1.12 terminal value, nthe remaining value of thedrainage structure in place at the end of the project design life.4. Summary of Practice4.1 This practice outlines a procedure for conducting anLCC analysis of two or more drai
14、nage pipe alternatives usingcorrugated metal pipe over a specified project design life. It1This practice is under the jurisdiction of ASTM Committee A05 on MetallicCoated Iron and Steel Products and is the direct responsibility of SubcommitteeA05.17 on Corrugated Steel Pipe Specifications. This prac
15、tice was prepared incooperation with Subcommittee B07.08.Current edition approved October 1, 2003. Published December 2003. Originallyapproved in 1994. Last previous edition approved in 1999 as A 930 - 99.2Annual Book of ASTM Standards, Vol 04.11.3Available from Office of Management and Budget, Wash
16、ington, D.C.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.identifies the project data and general assumptions necessaryfor the analysis and the method of computation
17、.5. Significance and Use5.1 LCC analysis is an economic method for evaluatingalternatives that are characterized by differing cash flows overthe designated project design life. The method entails calcu-lating the LCC of each alternate capable of satisfying thefunctional requirement of the project an
18、d comparing them todetermine which has (have) the lowest estimated LCC over theproject design life.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, r
19、ehabilitation, 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 that the former is the economically prefer-able
20、choice.6. Procedures6.1 The procedure for performing an LCC analysis fordrainage pipe applications is summarized in the followingsteps:6.1.1 Identify the project objectives, alternatives, and con-straints (6.2).6.1.2 Establish the basic assumptions (6.3).6.1.3 Compile data (6.4).6.1.4 Compute the LC
21、C for each alternative (6.5).6.1.5 Evaluate the results (6.6).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 theop
22、tions to be considered.6.2.2 An example 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 m
23、aterials and varyingconfigurations 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 sur
24、face flows onstreets, etc.6.3 Basic Assumptions:6.3.1 Establish the uniform assumptions to be made in theLCC analysis of all alternatives. These assumptions include theselection of discount rate, treatment of inflation, generalinflation rate, project design life, and desired comprehensive-ness of th
25、e analysis.6.3.2 Discount RateThe discount rate selected shouldreflect the owners time value of money. That is, the discountrate should reflect the interest rate that makes the ownerindifferent about paying or receiving a dollar now or at somefuture time. The discount rate is used to convert the cos
26、tsoccurring at different times to equivalent costs at a commonpoint in time.6.3.2.1 No single correct discount rate exists for all owners.Selection of the discount rate should be guided by the rate ofreturn on alternative investment opportunities of comparablerisk (that is, the opportunity costs of
27、capital) or, in the case ofsome public organizations, on mandated or legislated require-ments such as that contained in OMB Circular No. A-94.6.3.2.2 The discount rate may include general price inflationover the study period. This discount rate is referred to as thenominal discount rate in this prac
28、tice. 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 its correspondingreal discount rate (dr) are related as follows:dr51 1 dn1 1 I2 1ordn5 1 1 dr!1 1 I! 2
29、1 (1)where:I = rate of general price inflation.6.3.2.4 The same discount rate should be used when evalu-ating each design alternative. Table 1 contains a procedure tofollow when developing the discount rate. This procedure canbe applied by those who wish to select their own values as wellas those re
30、quired to follow mandated or legislated require-ments.6.3.3 InflationThis practice is designed to accommodateonly a uniform rate of general inflation. The LCC can becalculated in constant dollar terms (not including generalinflation) or current dollar terms (including general inflation).If the latte
31、r is used, a consistent projection of general priceinflation must be used throughout the LCC analysis, includingadjustment of the discount rate to incorporate the generalTABLE 1 Discount Rate Procedure1.0 GeneralThis procedure is intended to guide the user in developing areal discount rate, that is,
32、 the long-term rate of return over andabove the general inflation rate. This procedure can be used bythose required to use rates specified by mandate or legislatedrequirement, as well as those desiring to select their own values.This procedure does not recommend any specific rates; thatselection is
33、up to the user and should be made based on theconsiderations described in 6.3.2.1.1.1 Is there a discounted rate that must be used by policy, mandate, orlegislated requirements? (check one):1.1.1 _ Yes. If yes, the discount rate is _ %1.1.2 _ No. Proceed to 2.1.2 _ Does the discount rate in 1.1.1 in
34、clude inflation? (check one):1.2.1 _ Yes. If yes, the inflation rate is _ % (proceed to 2.1.4)1.2.2 _ No. The rate shown in 1.1.1 is the real discount rate (excludesgeneral inflation) and can be used as drin (Eq 3) and (4).2. If no discount rate is mandated, two approaches are possible:2.1 Select a
35、long-term percentage rate of return on invested money, overand above the general inflation rate. This value can be used as drin(Eq 3) and (4).2.2 Select a nominal discount rate (including general inflation): _ % =(dn).2.3 Select a long-term rate of general inflation: _% = (I).2.4 Calculate the real
36、discount rate (dr) for use in (Eq 3) and (Eq 4).dr51 1dn1 1 l2 1A930032inflation (6.3.2.2). The percentage change in the GNP deflatorand producers price index are two broad indicators of generalinflation.6.3.3.1 If the user desires or is required to treat inflation onan incremental (differential) ba
37、sis, or uniquely to each indi-vidual cost component (for example, energy costs), he or sheshould consult either TM-5-802-1 or Practice E 917, respec-tively.6.3.4 Project Design LifeThe project design life (3.1.9)should be established from mandated public policy, legislatedrequirements, or selection
38、by the owner based on situationrequirements. The same design life must be used for eachalternative under comparison and for all cost categories underconsideration. The potential for future obsolescence, that is, thepotential that future changes may modify drainage systemrequirements, should be consi
39、dered when selecting a projectdesign life.6.3.5 ComprehensivenessThe appropriate degree of pre-cision and detail to use in an LCC analysis is dependent on theintended use of the analysis. A less comprehensive or detailedanalysis may be sufficient for ranking many alternativesroughly, whereas a more
40、comprehensive analysis may benecessary for selecting from among a few close alternatives. Inany case, omitting significant factors from an LCC analysisdiminishes the usefulness of the results.6.3.6 Sensitivity AnalysisNo analysis can be more precisethan the accuracy of the data and assumptions used
41、in thecalculation. The LCC can be calculated for a range of assump-tions when uncertainty exists regarding basic assumptions (forexample, cost estimates, design life, discount rate, etc.). Theresults of these calculations will show the user the extent towhich the results are sensitive to variations
42、of the keyassumptions.6.4 Compilation DataCompile the following data specificto each alternative under consideration:6.4.1 Initial CostsThe estimated dollar amount of allcosts required to bring the alternative system to a point offunctional readiness.6.4.2 Material Service LifeThe number of years of
43、 ser-vice expected of the alternate under study. Material service lifevaries depending on the pipe material, environment, effluent,and application. Potential changes in environmental conditionsthat may affect the material service life should be considered.Job site tests, published reports, manufactu
44、rer product data,and local experience can be used to establish the service life foreach material. If the material service life is shorter than theproject design life (3.1.9), the analysis must include the futurecost to extend the service life sufficiently through rehabilitationor replacement in orde
45、r to at least equal the project 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 design life. Common costs (1.1) may be excludedwithout affecting the
46、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 CostAn estimate of the annual cost forlabor, power, and consumable materials and supplies requiredt
47、o operate a drainage system. Except for pumped systems, mostdrainage systems do not have significant annual operatingcosts.6.4.3.2 Maintenance CostsCost estimates and the fre-quency of any inspection, cleaning, and minor repair necessaryto keep the system operating at capacity during the projectdesi
48、gn life.6.4.3.3 Rehabilitation CostsThe cost of major repairs toextend the material service life to equal or exceed the projectdesign life. The years in which the rehabilitation are plannedshould be noted if more than one rehabilitation is anticipated.6.4.3.4 Replacement CostThe timing and cost esti
49、matefor complete replacement of any drainage system component.Care should be taken to determine whether the service life ofthe replaced material or component will at least equal theproject design life. If not, rehabilitation or further replacementwill be necessary.6.4.3.5 Terminal ValueThe value of the drainage systemat the end of the project design life. The potential residual orsalvage value of a drainage system is dependent on some of thefactors considered when establishing the project design life.For example, if a storm sewer
