Identifying the Alternatives

The next step of the process is to examine the alternative pathways to achieve the project objective. Technically, there may be two or three ways to achieve the improved quality. We must now compare the alternatives. In examining the different alternatives, many factors may be considered. However, these factors generally boil down to a few basic areas technical performance, cost requirements, schedule requirements, and relative risk. 

This is often an area where companies tend to get bogged down. The temptation is to examine an infinite number of cases. This is often an excuse for management to avoid making a decision. The job of the project team will be to pare down the cases to a few reasonable alternatives and examine them in detail. 

Back to our quality improvement project. The project team, at this point led by the Technical Manager, finds three different methods to remove the offending impurities. Technically, all three will produce an acceptable product Q for the new customer. Now the fun begins. Which project do we select How do we make sure we do the right project  

Each alternative must now be looked at critically. Process design will specify the equipment needed. Estimating will give the capital cost. It is important that each alternative is designed and estimated on a relatively equal basis. The absolute cost will be important eventually, but, at this point, the relative cost of each alternative is more important. Don t forget to include all costs, not just capital. Operating costs for the new system must be known to allow project profitability to be calculated. When defining each alternative, make sure the project risks are specified. These will include but may not be limited to  

For our Product Q project, we have determined that there are 3 alternatives that may be considered reasonable  

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The first step in using the AHP to analyze a decision problem is to hierarchically break down the decision problem (objective) into its constituent components and identify the alternatives to be evaluated. The resulting hierarchy consists of the overall objective (goal) and one or more levels of sub-objectives. The alternatives to be evaluated are added at the lowest level of the hierarchy. According to Saaty (1980, pp. 79-83) a cluster should not contain more than 7 elements because results from psychological tests show that 1+1-2 are the maximum number of elements a person can effectively compare simultaneously. 

Identify the parameter of interest such as the population mean, p, or the variance, a. State the null hypothesis, //g. Then identify the alternative hypothesis, //,. (The alternative hypothesis can be two sided or one sided.)... 

The aim and optimum result of this step is identification of a set of measures (programme of measures) which are perceived as a fair trade-off between different stakeholders interests, without encountering anyone s opposition and taking Articles 4.5-7 of the WFD into account (see Hattermann and Kundzewicz, 2007). If such an alternative cannot be found, another possibility is to identify the alternatives that hve... 

In this skeleton switch statement, expr is the test expression and constl and const2 symbolize the constants that identify the alternatives. In this example, each alternative is shown terminated by a break statement, which is common but not required. Without these break statements, flow of control would meander from the end of each alternative into the beginning of the following. This behavior is not usually what the programmer wants, but it is one of the possibilities that is present in C s switch statement. The break statement will be discussed further later. 

The initial step in an incremental analysis of conpeting alternatives is to identify the potential alternatives to be considered and to specify the increments over which the analysis is to be performed. Our first step is to rank the available alternatives by the magnitude of the capital cost. We will identify the alternatives as Ai, A2,. .., There are n possible alternatives. The first alternative, A, which is always available, is the do nothing option. It requires no capital cost (and achieves no savings). For each of the available alternatives, the project cost (capital cost), PC, and the yearly savings generated (yearly cash flow), YS, must be known. 

The PWRR is particularly applicable to regulated public utilities, for which the rate of return is more or less fixed by regulation. The principal objection to the PWRR method is that it is inadequate where alternatives are competing for a limited amount of capital because it does not identify the alternative that produces the greatest retimi on invested... 

The best few nonintegrated sequences can be identified most simply using the total vapor load as a criterion. If this is not satisfactory, then the alternative sequences can be sized and costed using shortcut techniques. 

The objective of an EIA Is to document the potential physical, biological, social and health effects of a planned activity. This will enable decision makers to determine whether an activity is acceptable and if not, identify possible alternatives. Typically, ElA s will be carried out for... 

The parametric method is an established statistical technique used for combining variables containing uncertainties, and has been advocated for use within the oil and gas industry as an alternative to Monte Carlo simulation. The main advantages of the method are its simplicity and its ability to identify the sensitivity of the result to the input variables. This allows a ranking of the variables in terms of their impact on the uncertainty of the result, and hence indicates where effort should be directed to better understand or manage the key variables in order to intervene to mitigate downside and/or take advantage of upside in the outcome. 

On occasion, a data set appears to be skewed by the presence of one or more data points that are not consistent with the remaining data points. Such values are called outliers. The most commonly used significance test for identifying outliers is Dixon s Q-test. The null hypothesis is that the apparent outlier is taken from the same population as the remaining data. The alternative hypothesis is that the outlier comes from a different population, and, therefore, should be excluded from consideration. 

Confirmation of the formation of the radicals during combustion reactions has been made by inuoducing a sample of dre flames into a mass spectrometer. The sample is withdrawn from a turbulent flame which is formed into a thin column, by admitting a sample of the flame to the spectrometer drrough a piidrole orifice, usually of diameter a few tenths of a millimetre. An alternative procedure which has been successful in identifying the presence of radicals, such as CHO, has been the use of laser-induced fluorescence. 

Risk sensitivity results are also very useful in identifying key elements in your existing loss prevention program. For example, suppose your fire protection system was assumed to have a very low probability of failure because you test it weekly. Fire protection failures may not show up as an important contributor to your total risk (because failure is so unlikely), but your total risk estimate may be extremely sensitive to any change in the probability of fire protection failures. Flence you should not divert resources away from testing the fire protection system unless the alternate use of funds will decrease risk more than the reduced testing will increase risk. 

It is often taken for granted that reduction of a waste will have environmental benefits. Though this is generally true, there are exceptions to the rule. For example, reducing one waste may give rise to pH imbalances or may produce another waste which is more difficult to treat, resulting in a net environmental disadvantage. Hence, there may be environmental trade-offs between the status quo and the alternatives identified. 

Design and development plans need to identify the activities to be performed, who will perform them, and when they should commence and be complete. One good technique is to use a network chart (often called a PERT chart), which links all the activities together. Alternatively a bar chart may be adequate. In addition there does need to be some narrative, as charts rarely convey everything required. 

The initial aim of the procedure is to generate a reasonable base case design that can be used for preliminary economic evaluation of the process. This can subsequently be optimized and/or compared with any process alternatives that are identified. The complete process is always considered at each decision level, but additional fine detail is added to the structure of the flowsheet at any stage. Established heuristics and equipment selection procedures are used together with new process synthesis insights to guide each flowsheet decision. 

In addition to the proactive uses of the SRK model described in the two previous sections, it can also be employed retrospectively as a means of identifying the underlying causes of incidents attributed to human error. This is a particularly useful application, since causal analyses can be used to identify recurrent vmderlying problems which may be responsible for errors which at a surface level are very different. It has already been indicated in Section 2.4.1 that the same observable error can arise from a variety of alternative causes. In this section it will be shown how several of the concepts discussed up to this point can be combined to provide a powerful analytical framework that can be used to identify the root causes of incidents. 

Since the mental model elicited by IMAS explicitly identifies the information needed to identify the causes of disturbances (and to distinguish among alternative causes), it can be used to specify the critical variables that need to be readily available to the process controller at the interface. This information can be used as an input to the design and upgrading of interfaces, particularly when new technology is being installed. 

Guidelines for Chemical Process Quantitative Risk Analysis (CPQRA Guidelines) builds on the earlier work to show the engineer how to make quantitative estimates of the risk of the hazards identified. The quantitative estimates can identify the major contributors to risk. They can also help to define the most effective ways to a safer process by indicating relative risk reduction from proposed alternate process safeguards and measures. 

Once the leant has been established, the review is conducted. Typically, the rc icw begins with the process inputs and proceeds through the syslcin to the outputs. Each of the What IF questions is addressed by identifying the hazard and it s consequence, and then recommending solutions or alternatives to alle ialc the risk. ... 

In contrast to the wealth of reactions in which N2O4 tends to behave as N0+N03, there is no evidence for reactions based on the alternative heterolytic dissociation N02" "N02". Earlier claims to have identified BF3 adducts such as [N02]+[0N0BF3] have been shown to be incorrect and the predominant products of the reaction of BF3 with N2O4 (and also with N2O3 and with N2O5) are, in fact, NO+Bp4 and N02+BF4". This latter compound had... 

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