Life cycle rating

Toloken, S., Groups Strive to Simplify Life-cycle Rating, Plastics News, Oct. 25, 2004, p. 12. 

In 1993, the United States medical device industry employed 282,000 people, averaging a growth rate of about 4% since 1975. Research and development spending in this industry outpaced that in virtually every other industry. Over 7% of sales were spent on research and development in 1993, amounting to a Httle less than 3 bHHon. This rate reflects both the rapid rate of innovation and short product life-cycle. Medical devices become obsolete far more rapidly than pharmaceuticals (qv), forcing companies continuously to be innovative. 

The balance between animal and plant life cycles as affected by the solubiHty of carbon dioxide ia the earth s water results ia the carbon dioxide content ia the atmosphere of about 0.03 vol %. However, carbon dioxide content of the atmosphere seems to be increa sing as iacreased amounts of fossil fuels are burned. There is some evidence that the rate of release of carbon dioxide to the atmosphere may be greater than the earth s abiHty to assimilate it. Measurements from the U.S. Water Bureau show an iacrease of 1.36% ia the CO2 content of the atmosphere ia a five-year period and predictions iadicate that by the year 2000 the content may have iacreased by 25% (see Airpollution). 

Culture a range of invertebrate species from the major phyla, preferably species with short life cycles. The effects of potential endocrine disrupting chemicals on growth rate, reproductive output, viability of offspring and sex ratio, and the vulnerability of different stages of the life cycle, can then be determined. 

FIGURE 16.1 Comparison of life cycle assessment and life cycle cost calculations. The result of LCA is (weighted) emissions and the present value of investment and operating costs, e.g,. in Euros. Note that in LCA calculations the present value coefficient is I, but the present value of LCC is always affected by interest rate and the length of the period. ... 

Caiciiiations can be sensitive to the interest rate (Fig- 16.2) and the time ol the calculation period (fig. 16.3), which is the utilization time or the life cycle of the device. Thus, it is often advisable to consider sensitivity analysis for these factors. Elements of uncertainty can also be found in the estimation of energy consumption and investment (in design phase at the pre-tender stage). 

FIGURE 16.5 Comparison of different ventilation unit combinations. The life cycle Is 20 years and the interest rate is A%. In sensitivity analysis the variation of the Interest rate did not change the order of different combinations signlBcantly. 

Capital investments can also be selected on the basis of other measures of performance such as return on investment, internal rate of return, and benefit-cost ratio (or savings-to-investment ratio). Flowever, care must be taken in the application of these methods, as an incremental analysis is required to ensure consistent comparison of mutually exclusive alternatives. Also, rather than requiring a separate value to be calculated for each alternative, as in the case of the life-cycle cost method, these other methods incorporate the difference between two mutually exclusive alternatives within a single measure. For example, the net benefits measure directly pressures the degree to which one alternative is more economically desirable than another. 

A real discount rate of 10% was used to convert all future expenses and savings into current dollars. This allowed calculation of the net present value of the savings and costs. Also calculated were the discounted payback period and the simple payback period. Each of these quantities was calculated over a life cycle analysis period of 20 years, the assumed life of the mechanical system. Maintenance costs were considered to remain constant in real terms. 

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