Evaluation of Individual Production Sites

The need to evaluate production sites can arise in different situations. Most obviously, a network optimization project resulting in the decision to establish new production capacity may require a site selection phase in one or more countries (cf. Chap. 2.4.4). Depending on the status quo, the task either is to identify and evaluate potential production sites or to choose the most suitable one from a set of existing sites. Conversely, if capacity is to be reduced potential closure candidates might have to be assessed to identify the one least suitable for future use. Additionally, as pointed out in Chapter 2.4.5, a regular evaluation of all production sites is also required in the context of site controlling. Here the objective is to rank a company s entire portfolio of existing sites to identify action needs. 

As discussed in Chapter 2.2.2 a broad range of criteria have to be considered if an in-depth assessment of individual sites is required. In practice matters are further complicated by the fact that the majority of sites host plants from multiple value chains. In this chapter a uniform decision support tool is developed to ensure consistent evaluations in all instances requiring site assessments. To this end Chapter 4.1 introduces the field of Multiple Criteria Decision Analysis (MCDA). Two different families of tools that could be applied to the decision problem at hand are discussed in greater detail in Chapters 4.2 and 4.3 respectively. As the use of Data Envelopment Analysis (DEA) for multiple criteria decision problems has been proposed in literature, too, the method is introduced in Chapter 4.4. An evaluation model for specialty chemicals production sites developed in cooperation with the industrial partner is presented in Chapter 4.5 and insights from application case studies are reported. 

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For over a decade, LNAPL occurrence has been investigated beneath an active refinery site in southern California. Numerous monitoring wells along with LNAPL samples have been used to evaluate the extent and character of LNAPL occurrence. LNAPL was found to occur as five pools. The main pools each consist of individual accumulations of distinct product types occurring under both perched and water table conditions. Two different recovery and mitigation strategies have been utilized. In relatively high permeability zones, a system of two-pump recovery wells was used to recover fluids recovered water is reinjected without treatment. In relatively low permeability zones, a system of one-pump recovery wells was used. In the latter case, recovered water is treated prior to disposal. 

The information available is of two types. (1) First is the dependence of rate on the kind of alkane, on the nature of the catalyst, on reactant concentrations and on temperature. (2) Second is the dependence of product selectivities or other descriptive factor (for molecules having three or more carbon atoms) on these variables. This separation is somewhat arbitrary, but the first type focuses on the rate-determining step, and leads us into a discussion of mechanism that lacks the refinements needed to understand the origin of selectivities and their variation with conditions. Some people have combined these two features by evaluating orders of reaction and activation energies for the formation of each individual product, and assume by implication that each reaction that can be formulated to give these products demands a different sort of site but the numbers that emerge can only be used in a qualitative way, and the differences in site architecture cannot be defined. This approach is therefore somewhat sterile, and the alternative, which is to treat the rate of product removal and product selectivities separately, is to be preferred and is the one adopted here. 

Compared to the commercial availability of took that characterize the performance of various human subsystems, instruments that quantify task attributes are much less prevalent. However, the perception that increased emphasis on this area will increase the utility of measures that characterize the human will likely motivate a substantial increase in the number and variety of products available for task characterization. In addition, factors such as the Americans with Disabilities Act (ADA), which encourages worksite evaluations and modifications to facilitate employment of individuals with disabilities and the increase in work-site related injuries such as carpal tunnel syndrome have led to an increased demand for such tools. 

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