1、Designation: A930 09Standard Practice forLife-Cycle Cost Analysis of Corrugated Metal Pipe Used forCulverts, Storm Sewers, and Other Buried Conduits1This standard is issued under the fixed designation A930; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n 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 covers a procedure for using life-cycle cost(LCC) analysis techniqu
3、es 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, constructio
4、n, 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 pr
5、esent 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 pri
6、or to use.2. Referenced Documents2.1 ASTM Standards:2E917 Practice for Measuring Life-Cycle Costs of Buildingsand Building Systems2.2 Other Documents:TM-5-802-1 Economic Studies for Military ConstructionDesignApplications (12/86)Federal Office of Management and Budget Guidelines andDiscount Rates fo
7、r Benefit-Cost Analysis of FederalPrograms and State Documents for Guidelines or Require-ments3. 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 ti
8、me value of money,expressed as a percent, used to convert the 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.
9、3.1.4 future costs, ncosts required 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 thatresult in reduction of the purchasing power of the dol
10、lar fromyear to year over time.3.1.6 initial cost, nthe total of all 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,
11、 nthe annual or periodic costs,such as inspection and cleaning, to keep 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 willprovid
12、e before rehabilitation or replacement is necessary.1This practice is under the jurisdiction of ASTM Committee A05 on Metallic-Coated Iron and Steel Products and is the direct responsibility of SubcommitteeA05.17 on Corrugated Steel Pipe Specifications. This practice was prepared incooperation with
13、Subcommittee B07.08.Current edition approved Nov. 1, 2009. Published December 2009. Originallyapproved in 1994. Last previous edition approved in 2003 as A930 - 03. DOI:10.1520/A0930-09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceas
14、tm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.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 S
15、tates.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 cost,
16、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 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 analys
17、is of two or more drainage pipe alternatives usingcorrugated metal pipe over a specified project design life. Itidentifies the project data and general assumptions necessaryfor the analysis and the method of computation.5. Significance and Use5.1 LCC analysis is an economic method for evaluatingalte
18、rnatives 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 and comparing them todetermine which has (have) the lowest estimated LCC over thepr
19、oject 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, rehabilitation, or replacement) when compared toan alternative with lower initial
20、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 choice.6. Procedures6.1 The procedure for performing an LCC analysis fordrainage
21、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 LCC for each alternative (6.5).6.1.5 Evaluate the results (6.6).6.2 Project Objecti
22、ves, 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 example is the design of a storm water drainagesy
23、stem 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 varyingconfigurations of catch basins, ponds, or underground deten-t
24、ion 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 Basic Assumptions:6.3.1 Establish the uniform assum
25、ptions 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 the analysis.6.3.2 Discount RateThe discount rate selected shouldreflect the owners
26、 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 costsoccurring at different times to equivalent costs at a commonpoint in time.6.3.2
27、.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 capital) or, in the case ofsome public organizations, on mandated or legislated f
28、ederal orstate requirements.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 practice. The discount rate mayalso be expressed as the real earning power of money over andabove general price inflat
29、ion, 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 1 (1)where:I = rate of general price inflation.6.3.2.4 The same discount rate should be used when evalu-ating each
30、 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 required to follow mandated or legislated require-ments.6.3.3 InflationThis practice is designed to accommodateonly
31、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 latter is used, a consistent projection of general priceinflation must be used throughout the LCC analysis, includingad
32、justment of the discount rate to incorporate the generalinflation (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) basis, or uniquel
33、y to each indi-vidual cost component (for example, energy costs), he or sheshould consult either TM-5-802-1 or Practice E917, respec-tively.6.3.4 Project Design LifeThe project design life (3.1.9)should be established from mandated public policy, legislatedrequirements, or selection by the owner bas
34、ed on situationA930 092requirements. 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 considered wh
35、en 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 comprehe
36、nsive 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 in theca
37、lculation. 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 of the k
38、eyassumptions.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 ser-vic
39、e 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, manufacturer prod
40、uct 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 order to at
41、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 relative
42、 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 requiredto operat
43、e 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 projectdesign life.
44、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 estimatefor
45、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 drai
46、nage 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 is being evaluated and a long (75years) project design life is used, con
47、sideration should be givento the risk of future obsolescence. The higher the likelihood offunctional obsolescence, the greater chance there may be noresidual or salvage value. However, if it is expected that thematerial could be removed and either reused or sold, the netcash value (in constant dolla
48、rs) represents the terminal value. Itis not recommended that a residual value be used to reflect aneconomic value for any remaining material life in excess of theproject design life. As an alternative, if it is felt that thefunctional requirements of the system under design are for anindefinite peri
49、od, consideration should be given to increasingthe project design life to an appropriately higher value, atwhich the residual value would not affect comparison of thevarious alternatives significantly.6.5 Computation of Life-Cycle Costs To compute theLCC for a drainage system, all relevant cost flows over thedesign life of the project are discounted back to the present andsummed.6.5.1 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
