User interface design specification

System specification proceeds much as before but has an added element of user-interface design. The normal artifacts of system specification—a type model and operation specs—are now accompanied by prototypes and UI specs describing the screens, dialog flows across windows, information presented and required, and reports. These user-interface elements are kept consistent with the type model and are reviewed through scenarios. 

Specification is the task of precisely describing the software to be written. It is a good rule to spend considerably more time with specification than with programming. Specification can be divided into several categories for describing functionality, user interface design, or technical aspects of the software. 

The user requirements specification, also referred to as requirements document or release plan, describes the requirements from an operator s point of view. This high-level document does not give any details about how the software actually is constructed, except that it may contain desired user interface designs to address a requirement. 

Training courses for user interface design and usability as well as corresponding certifications should be provided to show the value to the profession and to encourage enterprises to set up specific job positions for usability experts. This effort would foster the accumulation and development of related expertise in the industry. 

The GPCA safety requirements were designed on the basis of a preliminary hazard analysis for the controller of the pump. We found that almost half of the requirements can be related to user interface functionalities, and correctly capture basic human factors concerns. However, a hazard analysis specifically addressing user interface functionalities is needed to cover a more complete set of aspects related to human factors. We are currently starting this hazard analysis. Some examples of safety features and constraints that are currently not considered in the GPCA safety requirements and can potentially make the user interface design safer follows. 

FLOSHEET is part of a suite of programs called PROCEDE which has been developed for the efficient handling of all the information needed in process design. It aims to cover the complete process environment, using graphical user interfaces to facilitate the transfer of information, Preece et al. (1991). The equipment specification sheets given in Appendix G are from the PROCEDE package. 

Computational fluid dynamics (CFD) programs are more specialized, and most have been designed to solve sets of equations that are appropriate to specific industries. They can then include approximations and correlations for some features that would be difficult to solve for directly. Four major packages widely used are Fluent (http //www.fluent.com/), CFX (now part of ANSYS), Comsol Multiphysics (formerly FEMLAB) (http //www.comsol.com/), and ANSYS (http //www.ansys.com/). Of these, Comsol Multiphysics is particularly useful because it has a convenient graphical-user interface, permits easy mesh generation and refinement (including adaptive mesh refinement), allows the user to add phenomena and equations easily, permits solution by continuation methods (thus enhancing... 

The basic constructs of type, collaboration, and refinement support all levels of specification, architecture, and implementation. However, we also pay explicit attention to specific levels of architectural design logical and physical database mapping, technical architecture (including client-server and multitier peer-to-peer architectures), and user-interface modeling. The case study touches only on some of these aspects. 

User requirement specifications (URS) for the computerized system are provided by the pharmaceutical firm to the computer systems vendor. The vendor generates functional and design specifications as a basis for designing and coding software for the computerized system. The system is then built, together with all the interfaces to the hardware, and tested by the vendor. After installation of the computerized system, IQ, OQ, and PQ are performed at the pharmaceutical facility to verify that the system is able to meet the URS and design and functional specifications. 

Overall, most of the requirements for a process spectrometer/analyzer are straightforward to implement, but they do require attention at the design level. Another important area, which is FTIR specific, is the user interface and the need to provide for industry standard data communications. Standard software packages do exist for process instrumentation. For prototype development, and even for the front-end interface in a stand-alone mode of operation, software products, such as National Instraments Lab View and the Mathworks MatLab, are also important instrumentation development tools. Note that National Instruments also provides important computer-based electronics and hardware that meet most of the computer interfacing, and system control and communications needs for modem instrumentation. For practical installations, a product known... 

Computer systems validation personnel must also deal with design errors. A program that perfectly meets a lousy specification is a lousy program. Specifically for medical devices, books on software reliability tend to set aside the user interface issue, and treat it as the sole province of the human factor analyst. The reliability of a system is determined by how all its various parts, including the people who use it, work together. 

Once defined, the business process transactions can be configured within the development environment of the MRP II system. There are normally instances when it is easier to amend the business process to fit the standard functionahty of the MRP II product software than to make a customized bespoke modification. Any bespoke modiflcations, like the interfaces, must be fuhy documented in design specifications, test speciflcations, and test records. One important aspect to avoid during configuration is to set up the system to accept default user entries. There have been several recalls within the pharmaceutical industry because users failed to recognize that a default entry on their MRP II systems was incorrect. It is always a good idea to have positive user confirmation of key data entry or decision points. If defaults are stih required then make them... 

Usability testing is important for any software project and done during the design phase. It is extremely important because Web applications are used by many different users with different skill sets and expectations. Typically user interface prototypes are developed and tested by all types of anticipated users. Easy navigation through screens and applications are most important for Web applications. There are a couple of more considerations specifically for Web applications ... 

Justifications for the expert system s recommendations need to be clear and specific. Explanation facilities - such as the why and how queries often found in expert systems - often consist of replaying the logic used by the system to arrive at a conclusion. While this is sufficient for some applications, others require more in-depth justification including causal relationships and assumptions made. Design of the explanation facility must be tied to design of the user interface of the system. 

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