Reference Data Requirements

When performing either a HAZOP study or What-If analysis, it is essential that all necessary reference data be available for review and evaluation. Any and every type of data that pertains to the system or project under analysis should be examined to ensure that the review team is fully cognizant of all design criteria, functional intent, and operational requirements of the system. Once these elements are clearly established and understood, the consequences of any potential deviations (intended or otherwise) can be more fully explored and evaluated. 

TABLE 14.1 Typical Sources of Referrace Data to be Reviewed When Conducting a What-If Analysis and/or HAZOP Study 

History of losses from the existing or similar facilities 

Ergonomic or human factor elements (color coding, accessibility, practical use, languages and instructions, etc.) 

Personnel staffing and headcount levels ( distribution of personnel, levels of supervision, etc.) Evacuation routes and emergency response/action plans 

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The Data Model is extended by the Reference Data Library, RDL (cf. part 4 of ISO 15926). The RDL establishes the different terminologies (i.e., the Reference Data) required for the individual application domains. Particularly for the chemical process industries, taxonomies for the description of materials, plant equipment, physical properties, and units are introduced by refining the classes of the Data Model. The RDL is to be harmonized with the STEPlib hbrary of the AP 221 (cf. Annex M of ISO 10303-221). Currently (as of 2007), merging of these originally independent libraries is still in progress. So far, about 15,000 classes have been defined in the RDL. It is expected that the RDL will contain up to 100,000 standard classes in the end. 

Method References Data requirement Data collection Assessment type Approach Demand input Output... 

Design Procedures The procedures to be followed in specifying the principal dimensions of gas absorption and distillation equipment are described in this section and are supported by several worked-out examples. The experimental data required for executing the designs are keyed to appropriate references or to other sections of the handbook. 

Fragility testing This is a proprietory test to provide future reference data about an object, on its worthiness to operate under certain seismic conditions. When no seismic requirements are defined by the manufacturer the object is tested for its optimum capability. 

In principle, a measurement of upon water adsorption gives the value of the electrode potential in the UHV scale. In practice, the interfacial structure in the UHV configuration may differ from that at an electrode interface. Thus, instead of deriving the components of the electrode potential from UHV experiments to discuss the electrochemical situation, it is possible to proceed the other way round, i.e., to examine the actual UHV situation starting from electrochemical data. The problem is that only relative quantities are measured in electrochemistry, so that a comparison with UHV data requires that independent data for at least one metal be available. Hg is usually chosen as the reference (model) metal for the reasons described earlier. 

Regarding the multitude of NMR chemical shifts of specific compounds that are provided within the text, references for chemical shifts of individual compounds for the most part will not be cited. It is assumed that if such references are required, the reader can find them by a quick search using either MDL Crossfire Commander or SciFinder Scholar. The author found MDL Crossfire Commander the superior database for locating specific NMR data. 

The second difference relates to the definition of a cutoff time point for the evaluation of the difference factor and the Rescigno index. When cumulative data are available, evaluation of the difference factor or the Rescigno index usually requires a reference data set in order to define the cutoff time point for index evaluation (30). For the evaluation of fl and the , i.e., when the difference factor and the Rescigno index are evaluated from non-cumulative data, this difficulty does not exist, provided that the release process has been monitored up to the end (i.e., until dissolution of the drug is complete). At this point, it is worth mentioning that a similar conclusion cannot be drawn for the similarity factor (31) because application of this index to non-cumulative data is set apart by the careful scaling procedure required, in addition to the existence of a reference data set. The reason is that this index can continue to change even after dissolution of both products is complete. 

Semiempirical parameterizations require reliable experimental or theoretical reference data and are impeded by the lack, of such data. Such problems do not occur in ab initio or DFT approaches. 

The orthogonality of a set of molecular descriptors is a very desirable property. Classification methodologies such as CART (11) (or other decision-tree methods) are not invariant to rotations of the chemistry space. Such methods may encounter difficulties with correlated descriptors (e.g., production of larger decision trees). Often, correlated descriptors necessitate the use of principal components transforms that require a set of reference data for their estimation (at worst, the transforms depend only on the data at hand and, at best, they are trained once from some larger collection of compounds). In probabilistic methodologies, such as Binary QSAR (12), approximation of statistical independence is simplified when uncorrelated descriptors are used. In addition,... 

If the assessment endpoint is a distribution, or a statistic from a distribution (e.g., 95th percentile), it is essential to be clear how the distribution is interpreted (Suter 1998, p 129). If it is a frequency distribution, to what statistical population does the distribution refer For example, does the distribution represent a population of individuals, an assemblage of species, a number of locations treated with pesticides, or a series of time periods The answer to this question has substantial implications for the structure of the assessment model and the types of data required. 

Furthermore, isotope standard reference materials are required in different chemical forms for a multitude of elements in order to calibrate and evaluate isotope ratio measurements by mass spectrometry. In addition, reliable analytical data required in science and routine work will only be obtained by improving the quality assurance of the measurement procedures and also using interlaboratory comparisons of analytical results in round robin tests. 

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