Definition of requirements

The instrumentation requirements for macromolecular crystallography at the synchrotron are quite diverse and technically exacting. The diversity arises because of the different classes of experiment, namely  

There are certainly needs common to each category. 

In order to use the synchrotron X-radiation effectively, the white beam of photons diverging from the source must be collected by beam line optical element (s), and brought to a focus with a size approximately equal to the protein crystal size. The sample must be centred in the beam and oriented on a goniostat of some kind. The diffraction pattern has to be measured accurately and efficiently with a detector. In the case of monochromatic experiments the beam line optical scheme will include a monochromator of which there are several common types. There are some special needs for each experimental class. 

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Key elements of reactive hazard identification are owner-initiated review, chemistry review, review of unit operations, review of scenarios, definition of required testing, records testing, and interpretation of results for owner. 

No amount of printed material can substitute for proper definition of requirements, testing of component materials in the application, and careful formulation. Recommendation of a particular dye in a given application may be rendered useless by the use of a different set of functional additives in a color concentrate, for example. Some of the most common pitfalls are as follows ... 

Poor definition of requirements may lead to inadequate stability or overformulation for needs that do not really exist. In a competitive marketplace, of... 

If raw data are transcribed to a computer database, neither the electronically stored data nor the paper printout can substitute for the original. Information entered into the computer by direct data capture offers two options, however. The laboratory may elect to treat the electronically recorded information or a hard copy printout of the information as raw data. If the hard copy is retained, the magnetic media can be discarded or reused. If a laboratory elects to treat the magnetic media as raw data, it must retain an ability to display the data in readable form for the entire period during which that information is required to be retained. (See 58.195 for a definition of required retention periods.) If a change in computer systems would entail the loss of the... 

Clear definition of Requirements comes first. The next phase is the System (architectural) Design. Systemic design precedes always the detailed design. The modelling of units should be at the level of detail capable to capture the behaviour of the system. After solving appropriately the conceptual phase, the project may proceed with the Implementation and Units Test, and finally with the System Test. 

Pamela Zave provides a concise definition of Requirements Engineering (RE) ... 

One such model is the prototyping approach. The first delivery to the customer is a prototype of the envisaged system. The purpose of the prototype is to assess the feasibility of the product and to verify that the requirements of the customer have been understood by the developer and will be met by the system. The prototype is then thrown away (in fact, it is sometimes called a throwaway prototype), and development starts on the real product based on the now firmly established requirements. The prototyping approach addresses the difficulty of understanding the real requirements but it does not eliminate the time gap between the definition of requirements and delivery of the application. 

The acquisition of equipment is the next major part of effective equipment management. It follows and is indeed part of the equipment planning phase. Flowing from definition of requirements, specifications are developed. Bas on those specifications, a subset of possible equipment is evaluated for conformance to the specifications or standards, and purchase of the most appropriate equipment is initiated. When the equipment arrives at the hospital, the acceptance or incoming inspection of the equipment is a very common function that clinical engineering fulfils. 

Decomposition (WBS, IDEF) Breaking a category down into lower levels for sharper definition of requirements. The term can apply to project scope, activities, tasks, and projects. IDEF decomposes processes in a supply chain in a similar way. (Adapted from PMBOK Guide — 2000 edition)... 

The battery module is a chemical, thermal, electrical and mechanical system and is, therefore, to be developed with principles of systems engineering. The approach followed consists of defining a realistic process cycle from the definition of requirements to manufacturing. The tools and processes used for designing a conventional car were to be analyzed regarding the specificity of electrical vehicles. 

The Club thus helps to achieve more effective research, a more rapid and effective transfer and use of technology, the identification of best practice, the definition of requirements for education and training, and the dissemination of information. Importantly, it does this within a club atmosphere rather than a commercial environment. 

Costing, failure rates, mean time between maintenance, maintenance downtime, the environment (environmental condition), etc. are major factors that affect the development of requirements of specifications. Fig. X/1.0.1-1 shows typical stages involved in developing specifications from the definition of requirements. 

J-STD-001 andIPC-A-610 Industry Standards. These consensus industry association standards are widely recognized as the most common standards for requirements and workmanship for PCB assemblies, both nationally and internationally. They allow flexible definition of requirements based on three distinct classes of product, and the acceptability and performance requirements change based upon the contract provisions for the individual product as these classes are appUed. 

In the author s opinion, a clear definition of requirements, unequivocally formulated, understandable goals for all involved persons, shortcuts to information, and a critical estimation of possibilities/risks are more important, not only in analytics, than obtaining exemplary results such as low detection limit, correlation factors around 0.999, S gi smaller than 1%, or 30% less expensive equipment. 

Giving shape to the system on broad lines, including determination of the exact functionality of the components and definition of requirements at the element level. 

As will be explained below it is normally sufficient to consider the encircled categories in Figs. 16 and 17 for the definition of requirements to handle changed fields of view. 

To these stages are added the classic stages of each IT project, namely analysis of user requirements, definition of requirements, functional analysis, definition of external interfaces, definition and design of the architecture, development, on-site installation, functional testing, etc. A classical V cycle was followed. 

Definition of required training and/or familiarity with the system before access is permitted. 

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