Estimating contingency

Contingency charges are extra costs added into the project budget to allow for variation from the cost estimate. All cost estimates are uncertain (see Section 6.3.1), and the final installed cost of many items is not known until installation has been successfully completed. Apart from errors in the cost estimate, contingency costs also help cover... 

This is the maximum estimated contingency and is used to determine the area of the PRV. 

This may create more serious problems than individual local power failure. The impact of a particular bus bar design and the motors connected to a particular bus bar are very important in estimating contingency. It is often preferred that the electrical engineer and process engineer work together to establish the design of the bus bar. 

Groundwater and air quaHty monitoring ate requited for all faciHties that have the potential to generate emissions. There ate also requinements for contingency plans in the case of accidents, closure and post-closure plans, and financial requinements to ensure that closure plans can be foUowed. Permit appHcations must include an estimate of the composition, quantity, concentration, and frequency or rate of disposal, treatment, transport, or storage. 

A popular overall factor refinement, known as the Hand factor approach, uses a different factor to estimate overall costs for each class of equipment to cover all labor field materials, eg, piping, insulation, electrical, foundations, stmctures, and finishes and indirect costs, but not contingencies. Hand factors range from 4 for fractionating towers down to 2.5 for miscellaneous equipment. 

The estimated values for the various contributions are given in Table 9-53, resulting in an estimate of 4,280,000 for the total fixed-capital investment, including a contingency factor. 

Land. At this point, it should be possible to determine how much land will be required. Do not forget to include things like holding ponds, environmental buffer area, camp facilities, and rights of way or easements. It may be well to allow some contingency in initial cost estimates for land requirement increases, as more definitive design information becomes available. 

Type of Estimate Process Contingency Data Available... 

Regardless of the estimating method, a process contingency should be added to the total plant cost for feasibility studies. As discussed earlier, this contingency depends on the status of the project. For most factored estimates, on a first of a kind process that is fairly well defined, the process contingency should be 30%. 

The estimator s main objective should be to include all the known costs and keep the contingency for unknown and unexpected items to a reasonable level. 

While none of these kinds of variances can be precisely estimated you should consider them (and others you identify) in terms of their potential impact, and build an appropriate contingency percentage into estimates of... 

From such information even the inexperienced estimator can establish an approximation of the costs, provided he adequately visualizes the work functions and steps involved. From the same type of work reference, the experienced estimator can develop a realistic cost, usually expressed with certain contingencies to allow for unknown factors and changing conditions. The professional estimator wall normally develop cost charts and tables peculiar to the nature of his responsibilities and requirements of his employer. 

Contingency allowance, this is an allowance built into the capital cost estimate to cover for unforeseen circumstances (labour disputes, design errors, adverse weather). Typically 5 per cent to 10 per cent of the direct costs. 

About 40 percent of the Nd held by the mantle + crust system therefore resides in the crust. This estimate is contingent on neither the (143Nd/144Nd)bulk nor the (147Sm/144Nd)bulk ratio of the mantle-crust system (in particular, the chondritic... 

After installation, the total cost of equipment (direct permanent investment) is 6,557,000. Allowing 18% for the cost of contingencies and contractor fees ( 1,180,300), the total depreciable capital is estimated to be 7,737,000. Ten percent of this is assumed to cover the cost of startup, 773,700, giving a total permanent investment of 8,511,000. Working capital is estimated to cover accounts receivable that is, the sales of 30 days production of wafers (41,800 wafers), assumed to sell for 260/wafer, giving 10,868,000. Together with a 2-day inventory of wafers, valued at the product price, the total working capital is 11,520,000. Hence, the total capital investment is 20,031,000. 

Exploration of the scope of NPS in electrochemical science and engineering has so far been rather limited. The estimation of confidence intervals of population mean and median, permutation-based approaches and elementary explorations of trends and association involving metal deposition, corrosion inhibition, transition time in electrolytic metal deposition processes, current efficiency, etc.[8] provides a general framework for basic applications. Two-by-two contingency tables [9], and the analysis of variance via the NPS approach [10] illustrate two specific areas of potential interest to electrochemical process analysts. 

For preliminary estimates, a 15 to 20 percent project contingency should be applied if the process information is firm. As the quality of the estimate moves to definitive and detailed, the contingency value may be lowered to 10 to 15 percent and 5 to 10 percent, respectively. Ejq)erience has shown that the smaller the dollar value of the project, the higher the contingency should be. 

Contingencies An allowance for unforeseeable elements of cost in fixed investment estimates that previous experience has shown to exist. 

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