Background
The Designers' Sandpit project follows many years of successful
collaboration between Prof. Ken Swift at
the University of Hull and Mr Graham Jared at Cranfield University
aimed at the integation of Design for Assembly (DFA) techniques
within a Computer Aided Design (CAD) environment.
The antecedents of the current project lie in a previous
SERC ACME funded project. One of the key results of this was to
demonstrate that around 70% of data necessary for a DFA analysis
could be extracted either directly or by geometric reasoning from a
suitably enhanced CAD model of components and assembly
relationships.
A subsequent programme - the OPHIR project - explored the
relationship between assembly sequences and successful DFA
analyses. This research established that generation of a suitable
assembly sequence is fundamental to the success of any DFA analysis
and that the existing DFA methodologies themselves must be
modified, adapted and extended for use with an incomplete product
description, so-called 'Proactive DFA'. One of Ophir's more
important results in relation to the 'Sandpit' project is the
demonstration of a working prototype interactive environment for
the construction and validation of assembly sequences (see Figure
1). If a little basic with respect to its interface, this
demonstrator established the principles of concurrent design
generation and assembly evaluation, so called 'Assembly Oriented
Design'. Furthermore, reaction from a wide variety of industrial
companies, visited in the course of knowledge engineering tasks
within the OPHIR project, highlighted the potential of Assembly
Oriented Design and the need to encompass support for concept
design and early DFA evaluation, to ensure that product design is
optimised in the first instance. Indeed designers do not welcome
tools that evaluate completed designs and warn of forthcoming
expensive consequences at the manufacturing stage. This has been
described as the 'ugly baby' syndrome.
Figure 1 - The Ophir
Demonstrator