of specialized computer-based tools is generally limited only by the level of expertise the user has in exercising the various tools. The cut-and-paste metaphor is not a necessary part of this environment; however, when it is supported by the underlying operating system in a uniform manner, it greatly facilitates the rapid and effective transfer of many types of objects among different applications.
In theory, simulation outputs that are generated by using mainframe-based simulation systems can also be used by other programs. This can be accomplished by using other programs on the same mainframe or by downloading or otherwise transferring the data to a microcomputer for further processing. In practice, the former alternative is cumbersome and time consuming; mainframe systems may not be written to be used interactively, and the complexity of the most common mainframe operating systems favors efficient execution of repetitive procedures over providing flexibility for ad hoc data exploration and manipulation. The latter alternative, transferring data to microcomputers, is more promising, but it requires an export capability in the mainframe software that recognizes the characteristics of the target microcomputer environment. Mainframe software rarely reflects this orientation.
The rich applications environment possible in current microcomputing environments, together with easy mechanisms for transferring objects between applications, provides a relatively complete set of tools that microcomputer-based simulation systems can rely on for further specialized forms of processing. Having such tools in the environment removes much of the burden of having to provide peripheral functionality from the simulation system and allows designers and implementers of such systems to concentrate on improving the simulation system itself.
Summary
The above discussion illustrates the types of advances currently being made in software and the ways in which these advances can be used to make the next generation of microanalytic simulation models considerably simpler to use. The software environment of 1995 will be able to capitalize on the expected hardware advances.
We expect the software environment of 1995 to be characterized by, inter alia, the following elements of importance to microanalytic simulation activities:
a powerful graphical user interface, with tools for controlling the interface available to the operating system and to user programs and systems;
substantial advances in computer-based software engineering tools that will magnify the productivity of software designers and implementers, with strong orientation to graphical construction and display tools;
object orientation in systems and in programming languages that will be well developed and will provide a more mature paradigm for model construction
