Modeling languages requirements

Models that require internal convergence are best written as subroutines rather than spreadsheets, as more efficient solution algorithms can be used. Most user subroutines are written in FORTRAN or Visual Basic, though some of the simulators allow other programming languages to be used. 

The preceding five premises imply requirements that go beyond the scope of traditional computer-aided modeling systems. The modeling language should allow interaction with the modeler at a high level of abstraction, while the generated models should be explicit, transparent, fully documented, and usable without the need to consult manuals for assumptions or input/ output language conventions. 

In the absence of any formal modeling language for the representation of chemicals and chemical reactions, it is important to state a concise set of requirements that the desired language should satisfy. These requirements, consistent with the five premises of Section l.A are... 

Research efforts outside the domain of hazards analysis have established that expressive, fully declarative, domain-rich modeling languages are indispensable, if complex integrated systems capable of synthetic tasks are to developed. Furthermore, they have shown that computer-aided systems with advanced reasoning capabilities require the satisfaction of the following three conditions ... 

The system described herein for the automatic identification of hazards and the pathways leading to them utilizes two modeling languages which satisfy the above requirements. Specifically, we have used... 

Although the knowledge required to assess the potential for the prevention or dissipation of hazards is often held by different abstractions of the overall representation, the semantic relationships of the modeling languages afford efficient access to this information. The effect of protective processes, equipment restraints, sensors and control systems, emergency procedures, etc., are captured as constraints. Constraints may be embedded in the underlying representation as equations, or be associated directly to it via a constraint list, i.e., a collection of explicit process restraints. These restraints may be passive, such as materials of construction, or... 

The characteristics of creative design processes induce several requirements for adequate modeling languages. These requirements provide a basis for the evaluation of the existing approaches in the next paragraph. 

The variety of information conveyed by the different views in Figure 5.5 illustrates the need to visualize three-dimensional biopolymer structure data in unique ways that are not common to other three-dimensional graphics applications. This requirement often precludes the effective use of software from the macroscopic world, such as computer-aided design (CAD) or virtual reality modeling language (VRML) packages. 

---