Research Agenda

• Proactive DFA
• Concept Design
• Geometric Reasoning
• Product Complexity
• Expert Systems

Assembly- Oriented Design

Provides a 'Top-Down' design environment integrating DFA analyses, assembly sequence generation and manipulation of the product structure.

General Description

A large proportion of all product costs are determined at the design stage and much of this cost is incurred during assembly. In fact, there is evidence to suggest that in industry, products are still designed with at least 50% excess of parts and assembly content and undergo more complex assembly procedures than is necessary. Thus, the designer needs to consider assembly whilst developing product design in order to mitigate subsequent problems on the shopfloor. It is now accepted that product assembly considered at an early stage of the design, promotes study of the design as a whole, which has been proven to improve overall costs, quality and time to market. However, many current commercially available CAD packages still tend to concentrate upon 'component-oriented' design, where individual parts are modelled and then assembled to create the final product. Hence, a need has been identified for development of an 'assembly-oriented' CAD environment.

Design for Assembly (DFA) is a formal analysis procedure that facilitates consideration of assembly issues, bringing together multi-disciplinary teams to validate and evaluate designs and assess their suitability for manufacture and assembly. The methodology claims proven success in reducing part count, improving product quality and minimising assembly problems. Therefore DFA, integrated within a CAD environment, has been established as a significant step for consideration of assembly issues.

Assembly-oriented CAD goes further by providing a 'top-down' design software environment integrating DFA analyses, assembly sequence generation and manipulation of the product structure. Geometric reasoning is built into the underlying functionality to reduce subjective user input and a series of small expert systems provide information and advice for construction of the optimum assembly sequence. This concept was explored in a previous project. However, one of the major benefits of DFA is part count reduction through elimination or integration of parts - a better approach would be to ensure that an excessive number of parts is not incorporated into a design in the first place. Therefore, a more proactive approach to assembly oriented design is needed and it is this notion that The Designers' Sandpit project seeks to address.

• Proactive DFA - Development of a new methodology to facilitate development of efficient product designs and concurrently evaluate product structure and ease of assembly.
• Concept Design - Representation of design requirements, generation and selection of concept design alternatives using functional considerations.
• Geometric Reasoning - Analysis of CAD models for evaluation of manufacturing complexity and validation of assembly sequences.
• Expert Systems - Development of "Expert Advisors" to offer assistance to the designer at all stages of design from concept generation to sequence planning.