scholarly journals Life Cycle Cost Before, During and After the Design of Aircraft Propulsion Systems

Author(s):  
W. W. Shoemaker

Military engine manufacturers have been given a new set of ground rules by the Department of Defense and Congress when they vie for engine contracts. The manufacturers must establish that their engines are Life Cycle Cost (LCC) effective. This directive has resulted in engine manufacturers developing life cycle cost models, including airframes, to account for an overall weapons system. Once the model has been developed, it can be expanded allowing parametric studies of the engine/airframe system thereby developing a cost effective system. The Aircraft Engine Group of General Electric has developed such an LCC computerized model. This paper discusses various applications of the subject model as applied to an engine program before the design is finalized, during the detail design phase, and after the engine has been placed in production. The paper also includes examples of these applications of the model.

Author(s):  
A P Patra ◽  
P Söderholm ◽  
U Kumar

Life-cycle cost (LCC) is used as a cost-effective decision support for maintenance of railway track infrastructure. However, a fair degree of uncertainty associated with the estimation of LCC is due to the statistical characteristics of reliability and maintainability parameters. This paper presents a methodology for estimation of uncertainty linked with LCC, by a combination of design of experiment and Monte Carlo simulation. The proposed methodology is illustrated by a case study of Banverket (Swedish National Rail Administration). The paper also includes developed maintenance cost models for track.


2021 ◽  
Vol 13 (9) ◽  
pp. 4651
Author(s):  
Ming-Lun Alan Fong

The analysis of ventilation strategies is fundamentally affected by regional climate conditions and local cost databases, in terms of energy consumption, CO2 emission and cost-effective analysis. A systematic approach is covered in this paper to estimate a local economic and environmental impact on a medium-sized space located in two regions during supply-and-installation and operation phases. Three ventilation strategies, including mixing ventilation (MV), displacement ventilation (DV) and stratum ventilation (SV) were applied to medium-sized air-conditioned space with this approach. The trend of the results for three ventilation systems in the life cycle assessment (LCA) and life cycle cost (LCC) analysis is SV < DV < MV. The result of CO2 emission and regional LCC shows that SV is the lowest one in both regional studies. In comparison with the Hong Kong Special Administrative Region (HKSAR) during 20 Service years, the case analysis demonstrates that the percentage differences in LCC analysis of MV, DV & SV in Guangdong are less than 20.5%, 19.4% and 18.82% respectively. Their CO2 emission of MV, DV and SV in Guangdong are more than HKSAR in 10.69%, 11.22% and 12.05%, respectively. The present study could provide information about regional effects in the LCA and LCC analysis of three ventilation strategies emissions, and thereby help set up models for decision-making on high efficiency and cost-effective ventilation strategy plans.


Author(s):  
Varun J. Prabhakar ◽  
Peter Sandborn

Long life cycle products, commonly found in aviation, medical and critical infrastructure applications, are often fielded and supported for long periods of time (20 years or more). The manufacture and support of long life cycle products rely on the availability of suitable parts, which over long periods of time, leaves the parts susceptible to a number of possible supply chain disruptions such as suppliers exiting the market, counterfeit part risks, and part obsolescence. One solution to mitigating the supply chain risk is the strategic formulation of suitable part sourcing strategies (optimally selecting one or more suppliers from which to purchase parts over the life of the part’s use within a product or within an organization). Strategic sourcing offers one way of avoiding the risk of part unavailability (and its associated penalties), but at the possible expense of qualification and support costs for multiple suppliers. Existing methods used to study part sourcing decisions are procurement-centric where cost tradeoffs focus on part pricing, negotiation practices and purchase volumes. These studies are commonplace in strategic parts management for short life cycle products; however, conventional procurement-centric approaches offer only a limited view when assessing parts used in long life cycle products. Procurement-driven decision-making provides little to no insight into the accumulation of life cycle cost (attributed to the adoption and use of the part), which can be significantly larger than procurement costs in long life cycle products. This paper presents a new life cycle modeling approach to quantify risk that enables cost effective part sourcing strategies. The method quantifies obsolescence risk as “annual expected total cost of ownership (TCO) per part site” modeled by estimating the likelihood of obsolescence and using that likelihood to determine the TCO allowing sourcing strategies to be compared on a life cycle cost basis. The method is demonstrated for electronic parts in an example case study of linear regulators and shows that when procurement and inventory costs are small contributions to the part’s TCO, the cost of qualifying and supporting a second source outweighs the benefits of extending the part’s effective procurement life.


2012 ◽  
Author(s):  
Jin How Ho ◽  
Azlan Abd. Rahman

Artikel ini membincangkan kajian ringkas berkaitan analisis kos kitaran hayat terhadap langkah-langkah pembaikan pengaratan bagi jambatan dan struktur marin konkrit yang terdedah kepada karbonasi atau serangan natrium klorida daripada air laut atau sumber-sumber lain. Perisian kos kitaran hayat, Bridge LCC 2.0 digunakan untuk menjalankan analisi kitaran hayat untuk tiga kes kajian melibatkan kaedah nilai bersih kini. Keputusan kajian menunjukkan analisis kos kitaran hayat berkeupayaan untuk membantu jurutera dan agensi pengangkutan dalam menilai keputusan penyelenggaraan yang efektif berkaitan dengan masalah pengaratan. Ia boleh digunakan sebagai alat analisis ekonomi kejuruteraan yang membantu mantaksir kos-kos perbezaan dan membuat pilihan terhadap langkah pembaikan pengaratan yang berkesan. Analisis kos kitaran hayat bagi langkah pembaikan dipengaruhi oleh banyak pemboleh ubah seperti kos permulaan, kos penyelenggaraan, tahun kekerapan, dan jangka masa analisis. Amalan terbaik untuk analisis kos kitaran hayat bukan sahaja mengambil kira perbelanjaan oleh agensi, tetapi perlu mempertimbangkan kos-kos oleh pengguna dan analisis sensitiviti di sepanjang jangka hayat sesuatu langkah pembaikan. Kata kunci: Analisis kos kitaran hayat, jambatan konkrit, pengaratan, langkah, pembaikan, pemulihan struktur, keberkesanan kos, kaedah nilai bersih kini (NPV) This paper discusses a short study on life cycle cost analysis (LCCA) on corrosion remedial measures for concrete bridges and marine structures, which are subjected to carbonation or ingress of sodium chloride from sea water and other sources. Life cycle costing software, Bridge LCC 2.0, was used to perform life cycle cost analyses on three case studies, based on net present value method. The analysis of the results showed that LCCA is capable of assisting engineers or transportation agencies to evaluate optimum maintenance decisions in corrosion–related problems. It can be used as an engineering economic analysis tool that helps in qualifying the differential costs and choosing the most cost–effective corrosion remedial measures. Life cycle costs for the remedial measures are influenced by many costing variables such as initial costs, periodic maintenance costs, frequency years and analysis period. The best practice of LCCA should not only consider agency expenditures but also user costs and sensitivity analysis throughout the service life of a remedial measure. Key words: Life cycle analysis, concrete bridges, corrosion, remedial measures, structural rehabilitation, cost-effective, net present value method (NPV)


2017 ◽  
Vol 10 (1) ◽  
pp. 169-190 ◽  
Author(s):  
Hugo Raposo ◽  
José Torres Farinha ◽  
Luís Ferreira ◽  
Diego Galar

2011 ◽  
Vol 159 (1) ◽  
pp. 58-71
Author(s):  
Marian HOLOTA ◽  
Bartosz STACHURA

The article discusses the genesis of the subject undertaken by the engineering staff at OBRUM Ltd., presents the main feature of the multipurpose combat platform and identifies the basic components of the design. The illustrations show sample applications of the platform for building special vehicles. The summary presents the life cycle cost of the product.


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