Internet-Based Micro-Electronic Design Automation (IMEDA) Framework:Functional Requirements of Framework

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Functional Requirements of Framework

Design methodology is defined as a collection of principles and procedures employed in the design of engineering systems. Baldwin and Chung (Baldwin, 1995a) define design methodology management as selecting and executing methodologies so that the input specifications are transformed into desired output specifications. Kleinfeldt (1994), states that “design methodology management provides for the definition, presentation, execution, and control of design methodology in a flexible, configured way.” Given a methodology, we can select a process or processes for that particular methodology.

Each design activity, whether big or small, can be treated as a task. A complex design task is hierarchically decomposed into simpler subtasks, and each subtask in turn may be further decomposed. Each task can be considered as a transformation from input specification to output specification. The term workflow is used to represent the details of a process including its structure in terms of all the required tasks and their interdependencies. Some process may be ill-structured, and capturing it as a workflow may not be easy. Exceptions, conditional executions, and human involvement during the process make it difficult to model the process as a workflow.

There can be many different tools or alternative processes to accomplish a task. Thus, a design process requires design decisions such as selecting tools and processes as well as selecting appropriate design parameters. At a very high level of design, the input specifications and constraints are very general and may even be ill-structured. As we continue to decompose and perform the tasks based on design decisions, the output specifications are refined and the constraints on each task become more restrictive. When the output of a task does not meet certain requirements or constraints, a new process, tools, or parameters must be selected. Therefore, the design process is typically iterative and based on previous design experience. Design process is also a collaborative process, involving many different engineering activities and requiring the coordination among engineers, their activities, and the design results.

Until recently, it was the designer’s responsibility to determine which tools to use and in what order to use them. However, managing the design process itself has become difficult, since each tool has its own capabilities and limitations. Moreover, new tools are developed and new processes are introduced continually. The situation is further aggravated because of incompatible assumptions and data formats between tools. To manage the process, we need a framework to monitor the process, carry out design tasks, support cooperative teamwork, and maintain the relationship among many design representations (Chiueh, 1990; Katz, 1987). The framework must support concurrent engineering activities by integrating various CAD tools and process and component libraries into a seamless environment. Figure 75.1 shows the RASSP enterprise system architecture (Welsh, 1995). It integrates tools, tool frameworks, and data management functions into an enterprise environment. The key functionality of the RASSP system is managing the RASSP design methodology by “process automation”, that is, controlling CAD program execution through workflow.

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