Construction Cost Estimating: Process and Practices Leonard Holm, John E. . Schaufelberger, Dennis Griffin, Thomas Cole ebook PDF download. Construction cost estimating process and practices leonard holm john e schaufelberger dennis griffin thomas cole on amazoncom free shipping on qualifying. Construction Cost Estimating: Process and Practices [Leonard Holm, John E. Schaufelberger, Dennis Griffin, Thomas Cole] on ukraine-europe.info *FREE* shipping .
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This text comprehensively covers the fundamental cost estimating principles and processes used in commercial construction today. It covers theory, types of. Practices, 1/e eBook, you should refer to the link beneath and save the ebook or Download Construction Cost Estimating: Process and Practices, 1/e PDF «. Ebook Pdf Construction Cost Estimating Process And Practices contains important information and a detailed explanation about Ebook Pdf Construction Cost.
As a service to our authors and readers, this journal provides supporting information supplied by the authors. Technical support issues arising from supporting information other than missing files should be addressed to the authors. Limited financial resources and stringent company budgets necessitate quick capital estimation of pioneering biorefinery projects at the early stages of their conception to screen process alternatives, decide on project viability, and allocate resources to the most promising cases. This work reviews existing rapid cost estimation practices, which can be used by researchers with no previous cost estimating experience. The results illustrate discrepancies among the methods because their extrapolation on biorefinery data often violates inherent assumptions.
The author developed his method by correlating the energy losses of fuel manufacturing plants to the DCC and transfer duties of process segments to the ISBL costs. However, biorefineries often involve thermoneutral reactions for which the correlations are not recommended. All of the methods above could be applied, in principle, to calculate the capital costs of the biorefineries. Indeed, the methods have already been applied under the assumption that the regression models used in petrochemical processes could be extended to the emerging field of biorefineries.
Still, few plants operate on a commercial scale while the costs and process data are not shared with the public. Over the past 10 years, there have been efforts to update costing methods in quick ways. Costs for purchased equipment were derived from common engineering handbooks. Given the uncertainty around quick estimating, the authors decided to address the research hypothesis that different methods are or not consistent with each other, at least to a satisfactory degree.
For this purpose, the current work assesses five functional unit methods that are approved and well known among estimators, as well as Lange's thermodynamic cost correlations. We escalated all selected methods to a common currency, location, and basis year. We first compared the results with reference literature estimations and then with reported capital costs from commercial biorefineries.
For the latter, cost information was retrieved from a large database we have been compiling with cost and process information for commercial biorefineries that are already in operation worldwide or are announced to come online in the near future. The functional unit methods are Wilson's main plant item method; Taylor's process step scoring method; Bridgwater's correlations; Klumpar, Brown, and Fromme's process module method; and Petley's functional unit correlation Wilson studied 16 solid—fluid and fluid processing plants.
His method first calculated the average unit cost AUC of the main plant items; a term referring to all principal equipment items other than pumps.
All factors can be calculated from graphs and scales reported in Wilson's paper. Taylor developed his method by analyzing cost data of 45 real plants built in the UK during the s. The author reported a list of units that composed a process step and gave examples on the use of his method. The method can be used for capacities from 0. Bridgwater introduced various correlations in the late s to s.
He employed the traditional definition of the functional unit, not taking into account storage, pumping, heat exchanging, and multistreaming, although he considered the impact of mass throughput on the cost and the effects of weighed process pressure and temperature.
He did not assess the effect of materials of construction.
In , he presented similar equations for liquid and solid—liquid processes [Eq. They defined 12 process modules thoroughly according to the main physical parameter being changed, such as temperature, pressure, and number of streams, and thus, classified the main equipment items to one of these categories.
In the end, each process module consisted of the main equipment item and its auxiliary units. The authors claimed that their method was suitable for a broad range of processes and capacities. Petley worked on 79 processes and proposed variations of existing rapid methods, while introducing new parameters, such as workforce and number of reactions critical to the capital cost.
Finally, Lange's cost correlations based on thermodynamics are also used for the purposes of our study. First, we set as the common cost basis year and calculated the ISBL in millions of dollars for a greenfield plant built overnight in the US Gulf Coast. We compared the six proposed methods with the reported literature estimations. Then, we calculated the DCC in millions of US dollars for all processes to compare the results obtained by the methods with announced commercial plant costs retrieved from our database.
We report details on the escalation methodology and calculations for updating the aforementioned methods in the Supporting Information. We selected three biorefineries to assess the reliability of the estimation methods under study: The first two employ widely known technologies and are the most common biochemical and chemical biorefinery processes, respectively. Many commercial plants operate at a large scale around the world, some of which have made their capital investment known to the public, and thus, we were able to evaluate the precision of the results for each method.
Because there are only a few such commercial plants, this process is used to test the reliability of the cost methods in accurately predicting capital costs of pioneering biorefinery projects.
The validation processes represent the three broad process technologies employed in biorefineries: For most accurate application of the methods, we used detailed flowsheets involving rigorous material and energy balances for all processes; these are reported in the Supporting Information.
All processes handle solid—liquid systems apart from syngas ethanol, for which there is also a dominant gas phase and fall within the application ranges of the selected methods. Lange [Eq. The smallest deviations are observed for thermochemical ethanol and the largest for biochemical ethanol. Almost all methods tend to overestimate the actual ISBL of the biorefinery models.
However, as the reference costs are only estimations, their accuracy has to be verified. We have been compiling a database with historical costs and process parameters from existing or announced biorefineries worldwide. The information is collected mainly from press releases and announcements published by the companies. It should be noted that not all plants are greenfield projects: Soybean oil biodiesel biorefineries: Thermochemical ethanol biorefineries: Therefore, the OSBL for these two processes are expected to be underestimated.
The OSBL of thermochemical ethanol include the utilities and storage, the services, and the waste treatment facilities, and thus, the DCC is satisfactorily calculated. There are some data points for the thermochemical ethanol process, which are also strongly correlated.
However, for the soybean oil biodiesel process, the performance of the methods slightly changed: All relevant figures can be found in the Supporting Information. In this study, we performed two types of comparison: The reference literature estimate does not widely underestimate the cost either. For the deterministic comparison of the biodiesel model, Klumpar A and Lange [Eq. Because the results do not concur, we suggest that capital cost estimations for biodiesel processes are compared with numerous strongly correlated commercial plant data.
For the deterministic comparison of the thermochemical ethanol plants, Lange [Eq. In general, the largest deviations were reported for the bioethanol process. Almost all methods overestimated its actual cost; Wilson explicitly stated that his method might not be valid for such a process, whereas the methods of Klumpar and Taylor satisfactorily approximated the cost because they took into account multistreaming and reaction time.
The accuracy of Klumpar A was also because this method was developed based on natural source extraction processes, which involved solids grinding. Taylor's deviations were due to extensive corn handling involved in the process; this method was not primarily developed for such processes. Furthermore, the method put a high weight on step relative throughput and, given the high water usage, it led to slight overestimates.
Petley's result was also quite accurate: All Bridgwater's correlations deviated significantly from the reported DCC for attributing high scores to the process conversion. For the bioethanol process, this is rather small, once again due to high amounts of solvent, and according to Bridgwater, this makes the process more complex and more expensive. Lange's [Eq. As expected, Lange's [Eq. The cost was overestimated because of the weight given to the maximum process temperature.
The methods were developed during the s and, since then, there has been technical progress to reduce the cost of the pieces of equipment versus their operating temperature. The smallest deviations were reported for thermochemical ethanol. Furthermore, its syngas fermentation part is quite small and similar to a loop reactor or a gas bubble column typical equipment in chemical processes , and thus, its negative economies of scale do not interfere with the integrity of the methods.
As mentioned previously, the methods of Lange [Eq. Taylor's method gave very good overall results: Reaction time is taken into account as a crucial parameter that affects the cost of batch processes.
Significant process steps are thoroughly explained and multistreaming is taken into consideration. However, multistreaming, along with other parameters, such as storage time or materials of construction, are unlikely to be known in the early conceptual phase.
Klumpar A was accurate because it also took into account module throughput, but required full knowledge of the equipment needed to build the plant, along with its mass balances. Its high accuracy, despite its simplicity, is attributed to the large number of processes the author used to develop his method.
Furthermore, it is the most recent of the cost methods. Bridgwater's correlations were quite accurate for the biodiesel process, but they generally failed to correctly estimate the other processes. Finally, Lange's thermodynamic cost correlations were used as an attempt to investigate their applicability on biorefinery processes.
Although all methods entail a correct approach towards estimation, extrapolation to pioneering biorefinery processes must be applied with caution.
What is BIM? What are its Benefits to the Construction Industry?
The majority of techniques date back to the s or s, so retrieving suitable escalation factors is not only challenging and time consuming, but also introduces inevitable errors and deviations. We encourage researchers to recalculate the constants of the methods based on current process and cost data for the capital estimation of future biorefineries. We also suggest that budgeting of future biorefineries should also rely on reported capital costs of existing biorefineries, rather than on sole literature estimations or cost correlations, whenever possible.
As numerous biorefineries are lined up for commercial scale, there is a strong incentive to amend and improve shortcut cost models to ensure correct budgeting for successful project commercialization. Embed Size px. Start on. Show related SlideShares at end. WordPress Shortcode.
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Views Total views. Actions Shares. Embeds 0 No embeds. No notes for slide. Process and Practices Download by - Leonard Holm 1. The benefits can be packaged in a program that will most likely yield desirable outcomes. As a cautionary step, consider the cost to stand up the program, the cost to incur the chain of activities for the identified investment such as implementation, operation, and maintenance from both quantitative and qualitative perspectives.
When properly done, cost analysis provides the following utility to the program:. An art, not a science. As with any discipline, the actual application and practice of cost analysis is more difficult than the academic description. It is seldom the case that the process outlined above can be applied with complete precision. In most cases, many factors conspire to force the SE and the cost estimator to step "outside the box" in completing a cost estimate. When data is unavailable.
Data to support the estimate is often not readily available through the customer organization. Finding supportable data often requires creative thinking and problem solving on the part of the SE and cost estimator.
An example is an AoA in which one of the alternatives was to build roads. The agency in question did not possess any in-house knowledge on road construction, ancillary costs such as drainage ditches and easements , or permit and legal requirements for the construction of several hundred miles of access road. The situation required reaching out to the civil engineering community and several state departments of transportation in order to bridge the knowledge gap and obtain the information in question.
This resulted in a detailed and supportable estimate that the customer was able to use in justifying managerial decisions. Adaptability is key.
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As stated in the cost estimation development discussion, there is no single way to construct a cost estimate—too much depends on the details of the circumstances at hand. An estimator cannot do a parametric estimate, for example, if the data and situation do not support that approach. Another AoA provides an example of this.