1、Designation: A930 09 (Reapproved 2014)Standard 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 oforigi
2、nal 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 covers a procedure for using life-cycle cost(LCC)
3、 analysis techniques 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 engine
4、ering, construction,maintenance, rehabilitation, or replacement, over a specifiedperiod of 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
5、 based on 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
6、 limitations prior 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 andD
7、iscount Rates for 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, n
8、the investors time 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 constructi
9、on alternatives.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
10、power of the dollar 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 m
11、aintenance cost, 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 stru
12、cture willprovide before rehabilitation or replacement is necessary.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 se
13、rvice life of a specific alternative.3.1.11 replacement cost, 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.1This practice is under th
14、e 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 Subcommittee B07.08.Current edition approved Nov. 1, 2014. Published November
15、2014. Originallyapproved in 1994. Last previous edition approved in 2009 as A930 - 09. DOI:10.1520/A0930-09R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the s
16、tandards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Practice4.1 This practice outlines a procedure for conduc
17、ting anLCC analysis 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 f
18、or 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 and comparing them todetermine which has (have) the lowest estimat
19、ed 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, rehabilitation, or replacement) when compared toan alternative wi
20、th 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 choice.6. Procedures6.1 The procedure for performing an LCC anal
21、ysis 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 LCC for each alternative (6.5).6.1.5 Evaluate the results (6.6).6.
22、2 Project Objectives, Alternatives, and Constraints:6.2.1 Specify the design objective that is to beaccomplished, identify alternative systems or designs thataccomplish that objective, and identify any constraints thatmay limit the options to be considered.6.2.2 An example is the design of a storm w
23、ater 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 varyingconfigurations of catch basins, ponds, or unde
24、rground 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 Basic Assumptions:6.3.1 Establish th
25、e 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 the analysis.6.3.2 Discount RateThe discount rate selected shouldref
26、lect 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 costsoccurring at different times to equivalent costs at a commonpoin
27、t 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 capital) or, in the case ofsome public organizations, on mandated
28、or legislated federal 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 gener
29、al 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:dr511dn11I2 1ordn5 11dr!11I! 2 1 (1)where:I = rate of general price inflation.6.3.2.4 The same discount rate should be used when evalu-ati
30、ng 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 required to follow mandated or legislated require-ments.6.3.3 InflationThis practice is designed to accommoda
31、teonly a uniform rate of general inflation. The LCC can becalculated in constant dollar terms (not including generalinflation) or current dollar terms (including general inflation).TABLE 1 Discount Rate Procedure1.0 GeneralThis procedure is intended to guide the user in developing areal discount rat
32、e, that is, the long-term rate of return over and abovethe general inflation rate. This procedure can be used by those requiredto use rates specified by mandate or legislated requirement, as well asthose desiring to select their own values. This procedure does notrecommend any specific rates; that s
33、election is up to the user andshould be made based on the considerations 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
34、 in 1.1.1 include inflation? (check one):1.2.1 _ Yes. If yes, the inflation rate is _ % (proceed to 2.4)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
35、 Select a long-term percentage rate of return on invested money, over andabove 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 Calculat
36、e the real discount rate (dr) for use in (Eq 3) and (Eq 4).dr511dn11l2 1A930 09 (2014)2If the latter is used, a consistent projection of general priceinflation must be used throughout the LCC analysis, includingadjustment of the discount rate to incorporate the generalinflation (6.3.2.2). The percen
37、tage 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 uniquely to each indi-vidual cost component (for example, energy costs), he or sheshould consu
38、lt 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 based on situationrequirements. The same design life must be used for eachalternative unde
39、r 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 when selecting a projectdesign life.6.3.5 ComprehensivenessThe appropriate degree of preci-sion a
40、nd 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 comprehensive analysis may benecessary for selecting from among a few close alternatives. Inany case, o
41、mitting 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 thecalculation. The LCC can be calculated for a range of assump-tions when uncertainty exists regard
42、ing 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 keyassumptions.6.4 Compilation DataCompile the following data specificto each alternative under
43、consideration:6.4.1 Initial CostsThe estimated dollar amount of all costsrequired to bring the alternative system to a point of functionalreadiness.6.4.2 Material Service LifeThe number of years of serviceexpected of the alternate under study. Material service lifevaries depending on the pipe materi
44、al, environment, effluent,and application. Potential changes in environmental conditionsthat may affect the material service life should be considered.Job site tests, published reports, manufacturer product data,and local experience can be used to establish the service life foreach material. If the
45、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 least equal the project design life.6.4.3 Future CostsCost estimates should be made for allsignif
46、icant 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 ranking of the alternatives understudy. The cost estimates should be made in constant dollars(no
47、t 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 operate a drainage system. Except for pumped systems, mostdrainage systems do not have significant annu
48、al 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.6.4.3.3 Rehabilitation CostsThe cost of major repairs toextend the material service life to equal
49、 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 estimate forcomplete replacement of any drainage system component. Careshould be taken to determine whether the service life of thereplaced material or component will at least equal the projectdesign life. If not, rehabilitation or further replacement will benecessary.6.4.3.5 Terminal ValueThe value of the drainage system atthe end of the
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