Making Trade-Off Decisions

Before turning to a description of the Safe System, it is worth exploring further the typical policy context in which decisions abont road transport system design and operation are made. We conclnded Chapter 3 with an outline of the myriad objectives confounding the development of transport policy. Let us now develop this a little further. 

Second, there are debates abont how best to establish the true costs for individual elements—for example, on injnry, whether we should count aU the costs actually incurred for injury at various levels (loss of earnings, hospital costs, damage repair costs, etc.) or whether we shonld estimate the community s willingness to pay to save a disabling injury or a life. 

In New Zealand, the government not only required positive benefit-cost ratios before a project could proceed, but also mandated that the economic returns must reach a prescribed positive level. When this policy was introduced, safety projects became uncompetitive. The traffic safety specialists made a successful case for a switch from the direct cost method to the willingness-to-pay method for estimating the dollar value of a statistical life. The switch resulted in an approximate doubling of the value of a life and got a lot more safety projects over the line in the benefit-cost competition. Sadly, traffic safety advocates in New Zealand currently bemoan a failure to adequately adjust overtime, the values derived of this paradigm shift of well over a decade ago.  

There can be no doubt that whatever the decision-making method, games will be played by advocates seeking decisions in their favour. This is not to suggest that the New Zealand safety specialists were behaving inappropriately they were simply 

Eliminating Serious Injury and Death from Road Transport 

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HP had to make trade-off decisions in its supply chain. These decisions affected product and process design. The company found that the lowest manufacturing cost for a particular product might be achieved by creating an assembly of specialized parts. This meant that each product had unique parts that could only be used in that product. There was no attempt at achieving parts commonality across products. 

Tangible support means not only resources but also standing relative to other company priorities. PSM needs legitimacy as a business objective to hold its own in situations requiring a trade-off between long-term process improvement and short-term commercial considerations. No matter how deeply committed safety professionals may be, this legitimacy can only be conferred by top management, who ultimately must make those trade-off decisions. 

A word of caution is needed here. To develop a separation that is dependent upon a high number of theoretical plates is not ideal. A small decease in efficiency during use could make the column useless for that separation. Also, when replacing the column, remember that the next column may not have sufficient efficiency to be useful. Overall, the proper choice for flow rate is a trade-off decision which must be made in the context of the analysis requirements. 

Demand orchestration The process of making trade-offs market to market based on the right balance of demand risk and opportunity. These trade-off decisions are dependent on the use of advanced analytics to sense and shape demand simultaneously. 

Section 3.8.1 Trade-off Analyses. Describes the studies planned to make trade-offs among stated requirements design project schedule functional and performance requirements fimction task and decision allocation between human, software, and hardware and Ufe cycle/design to cost. Describes the use of criteria for decision-making and trade-off of alternative design solutions. Includes a description of technical objectives, criteria and weighting factors, and utility curves as appUcable. Also describes the methods and tools planned to be used and interfaces with the integrated database. 

Making trade-offs between conflicting, noncommensurate objectives is at the core of decision making. Uncertainty simply adds to the difficulty. For example, consider making decisions about aircraft safety. There is an inherent trade-off between the thoroughness of inspections of people and baggage and delays. The more carefully people and baggage are examined, the less likely a... 

There are other decision-making models that better describe how organisations actually arrive at decisions. Organisations that apply a bureaucratic model of decision-making will apply pre-defined rules and procedures rather than making trade-offs between different action alternatives. This approach will reduce the demands on the decision-maker s informationprocessing capabilities. 

In the development of new products, optimization of the fermentation medium for titer only often ignores the consequences of the medium properties on subsequent downstream processing steps such as filtration and chromatography. It is imperative, therefore, that there be effective communication and understanding between workers on the upstream and downstream phases of the produc t development if rational trade-offs are to be made to ensure overall optimahty of the process. One example is to make the conscious decision, in collaboration with those responsible for the downstream operations, whether to produce a protein in an unfolded form or in its native folded form the purification of the aggregated unfolded proteins is simpler than that of the native protein, but the refolding process itself to obtain the product in its final form may lack scalabihty. 

There is no systematic approach to exploiting flexibility. Upper management tends to make decisions that are too fixed and does not communicate well the trade-offs that should be applied when the future is different from its central assumption. For example, those implementing decisions may receive a deadline for completion of a trial, rather than a target completion date with guidelines on the value of different completion dates to the business and how to respond accordingly. 

A recent review of option models in drug development, co-authored by a biostatistician from AstraZeneca in Molndal, Sweden [14], suggests that there has up to now been a lack of appreciation among pharmaceutical executives of the value that statistics could bring to the decision making process. This review quantifies the value of information that could terminate unsuccessful projects early and assesses the time-risk trade-off. It proves that projects split... 

It may be more appropriate for the decision-making team to express preferences after the need for trade-off between the different compounds found has become apparent via the search results. Visualization and quantitative analysis techniques can then be used to reveal the trade-offs in the problem, facilitating the choice of a single compound, or a candidate and one or more backups that have different risk profiles. 

New combinations of simulation and optimization allow a much wider set of R D decision making processes to be optimized, at least approximately, than in the past. This exciting new approach has been developed to solve many problems thought to be impossible to solve with classic options analysis. The idea is to trade off the exactness of the optimization for the ability to look at more complex situations [21]. 

There are many considerations to partitioning the components, with trade-offs on flexibility, reuse, and performance. This chapter discusses these trade-offs and provides a set of patterns for making these decisions. 

The decision about which error is more important is not a scientific question that can be resolved through technical analysis. It is a value choice. Of course, better scientific knowledge reduces the probability of making incorrect inferences abouf healfh effects. But even in situations of high certainty, the choice between false-positive and false-negative errors remains. And people invariably weigh the trade-offs differenfly. 

Making decisions about risks to health and the environment is difficult for Congress, for regulatory agency administrators, for officials of industry, and for the public that awaits the decisions. Questions about science, economics, trade-offs, and uncertainty seldom have clear-cut answers. Many countries, many international treaties, and many environmental organizations have offered the precautionary principle as a shibboleth, a near-magic principle, to guide decisions about risks. 

In my opinion, the PP should rarely be used to make decisions, and never by Western advisers to LDCs. If the PP is to be adopted more broadly, decisions about adoption must genuinely be made by those worst affected by its implementation, with full accounting of cost-benefit and risk-risk trade-offs. 

Some of the problems that concern the proper methods for consideration of several different objectives in reservoir planning are discussed. Classical systems analysis approach to decision making for multiple objective problems is outlined and the inherent difficulties associated with multiple objectives and subjective estimates are identified. Techniques used in reservoir design and operation are reviewed. An alternate technique for considering noncommensurate, objectives, which relates the objectives in terms of real trade-off costs and eliminates the need for a priori estimates of objective worth is presented. The method is illustrated with three examples, including a reservoir operation problem and a cooling tower design problem. 31 refs, cited. 

A profound understanding of the company s fundamental value and actual company market valuation is also a prerequisite for making more advanced financing choices. Dealing with capital market deviations requires informed decisions on the trade-off between the benefit and cost of financial flexibility. 

Given the uncertainties as to the amounts and types of demand that an infrastructure may have to face, decisions involving trade-offs between the various attributes of dependability (e.g., between security and availability) are likely to be uninformed initially. In essence the problem is that infrastructure dependability also needs to be capacity engineered—and means provided of making effective trade-offs between the various dependability attributes, as their relative importance changes. This can be a major challenge. 

Furthermore, it is important to consider the accuracy and available resources when defining a mixture problem. It can be difficult to determine the accuracy and costs beforehand, because accuracy often trades off with costs, and it is influenced by data availability and the actual risk level. Efficiency considerations imply that an assessment should be as cheap as possible, but sufficiently detailed to make a motivated decision. For site-specific assessments, a detailed and costly assessment is necessary only when the actual risks are close to the level that is considered unacceptable. For other outcomes, for example, when the actual risk is much lower or higher than the unacceptable level, a more crude and cheap assessment may suffice. Similar reasoning applies when deriving safe exposure or concentration levels. If limited data are available, a conservative value may be derived. If implementation of this conservative value turns out to be too costly, it is worthwhile to invest resources in gathering additional data and subsequently deriving a more accurate value. This is reflected in the loops of the risk assessment approach (Figure 5.1), which has resulted in many tiered approaches, such as those discussed in Section 5.4.4. 

The final step in the decision making process should be the selection of risk management options. Once the different options are evaluated, a decision has to be made as to which options are selected and which rejected. This decision is obvious if one or more options turn out to be dominant (relatively better on all criteria). Otherwise, trade-offs have to be made that need legitimisation (Graham and Wiener 1995). A legitimate decision can be made on the basis of formal balancing tools (such as cost-benefit or multi-criteria-decision analysis), by the respective decision makers (given his decision is informed by a holistic view of the problem) or in conjunction with participatory procedures. 

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