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Function metrics make early design evaluation possible. A simple definition of function as a pair of behavior expressions that map the utilized part of a component behavior to an intended part of a device behavior enables formal definition of several useful metrics for engineered devices such as sharing, overload, modularity, and criticality. These function metrics can be used to evaluate properties of a given configuration of components in a device as well as to compare alternative configurations of devices for the same design intents. A program called Teleometrics has been implemented that models function representations of devices as graphs and generates function metrics. Four patented accelerometers used for automotive crash sensing are modeled, evaluated, and compared using Teleometrics.

Naive interpretations of concurrent engineering may expect extreme parallelization of tasks and simultaneous accommodation of multiple perspec tives In fact, from our efforts at modelling tasks in a MEMS (micro-electro-mechanical systems) pressure sensor design project, it appears that the structure of tasks and the product itself result in evolving contexts and scenanos of decision and data-flow that have a significant impact on the occurrence of conflicts among perspectives and mechanisms for their resolution This paper refines a previously described information model for defining evolving contexts of product model aspects, and team member perspectives, with software agents acting on behalf of team members to execute tasks The pressure sensor design project is analyzed in the framework of this information model Alternative scenanos of decision and action for design of the pressure sensor are modelled as design process plans The impact of contexts and design plans on the occurrence and resolution of conflicts is investigated. Conflicts between perspectives occur In supplier-consumer data flows, interface definition data flows, and shared output data flows during execution of these plans We present a technique for negotiating such conflicts by axiomatic negotiation models using analytical mechanisms Negotiation protocols based on these mechanisms propagate utility functions between decision parameters and conflict parameters, and explore the space of agreement points so as to suggest negotiated solutions

Design synthetic reasoning is a methodology to support the process of design synthesis and includes within its scope support for associated processes of design verification, behavior derivation, and function justification. The design synthesis of machines is viewed as the development of a specification of required behavior, and transformation of the specification into the description of a structure (or assembly) of machine components. In this paper, the process of design synthesis is modeled as a sequence of applications of transformation rules. These rules either respecify, elaborate, reduce, or reformulate the expression of required behavior, and ultimately allow matching and selection of structurally compatible machine components and relationships from a design library. The specification of required behavior for a simple rotary actuator is developed and progressively transformed to synthesize the structures of two different patented rotary actuating devices. The ability of both devices to produce the required behavior is verified, and the property of self-locking for both the devices is derived from the structure descriptions. The functions (purposes) of components and relationships in each device are extracted from the trace of transformation rules applied during the verification and derivation process for each device.

This paper presents in three parts a uniform methodology, called design synthetic reasoning, to support the process of design synthesis and associated processes of design verification, behavior derivation and function justification. The methodology is demonstrated on two patented devices for rotary actuation. The first part of the paper develops a representation scheme for machine designs. In the second part, the design synthesis of machines is viewed as the development of a specification of required behavior, and transformation of the specification into the description of a structure (or assembly) of machine components. The process of design synthesis is modeled as a sequence of applications of transformation rules. These rules either respecify, elaborate, reduce or reformulate the expression of required behavior, and ultimately allow matching and selection of structurally compatible machine components and relationships from a design library. The specification of required behavior for rotary actuation is developed and progressively transformed to synthesize the structures of the two patented rotary actuating devices. In the third part of the paper, the ability of both devices to produce the required behavior is verified, and the property of self-locking for both the devices is derived from the structure descriptions. The functions (purposes) of components and relationships in each device are extracted from the trace of transformation rules applied during the verification and derivation process for each device.

Machine elements and systems are represented for use in a design library to support the tasks involved in machine design. Machines are modeled as systems decomposable hierarchically from both the views of structure and behavior. Systems and their decomposed structures are represented algebraically using set and list primitives while behaviors are represented using typed predicate logic. The function, i.e. purpose, of subsystems in a machine system is also represented. Procedures to support design verification, design selection and design synthesis using algebraic and logical transformation rules are presented. The development of the representation scheme and reasoning procedures are illustrated with simple examples from machine design.

This chapter describes the application of seven approaches to support three basic task types of design (design selection, parametric design, and design synthesis). The specialization of these approaches to practical design techniques is analyzed and illustrated with examples.

This paper analyzes the information environment of a product development program in a manufacturing enterprise as a domain in which intelligent agents can facilitate coordination. The information environment refers to information accessed, shared and generated in a product development program. The analysis suggests a structure for defining agents and agent interactions, and clarifies coordination needs in the context of the product development process. An architecture of intelligent agents embedded in a coordination environment is proposed as a means of providing infrastructure and process support to product development. The process of extension of requirements, and the selection and parametric refinement of handbook design solutions of a relief valve is used to illustrate the analysis and architecture for coordination in product development. The functional requirements identified for product development coordination are: (a) explicit representation of development team perspective and product model aspect definitions and mappings among them, (b) encapsulation of views and changes of the product models by intelligent agents, and (c) management of scenarios of interaction between perspectives through their agents. Representation of the dynamics and hierarchy in product development environments is outlined.

A large structural analysis problem, involving the solution of 11448 equations with an average front width of about 350, was solved on a minicomputer. This mathematical model resulted from the application of the finite element method, using flat shell elements, to determine the stress levels induced in the carriage of a stacker-reclaimer due to design loads. Computer programs were developed for analysis; the frontal solution procedure with a restart facility and other modifications were used for the solution of the finite element equations. A scheme was developed and employed to solve such large problems on a minicomputer in spite of the limited computing speed and disc storage space available. Seven loads cases were analyzed and areas of high tensile and compressive stress identified.