DRed 2.0: A Method and Tool for Capture and Communication of Design Knowledge Deliberated in the Creation of Technical Products
Contents
• Introduction
– DRed project and research approach
– Issue-based design in Rolls-Royce (RR) using DRed 1.0.8
– Affordance-based
design & FAD modeling – Research question
• DRed 2.0.x information model
– Blocks & relations – Decomposition &
transclusion
• Application example
IP shaft power off IP shaft power offIP shaft power off
DRed project and research approach
• Has been running for 7 years of close collaboration between EDC & RR • Research approach follows that pioneered at CMU by n-dim group:
– Yoram Reich, Eswaran Subrahmanian here at ICED
– Supporting software infrastructure for both information modelling and rapid design tool prototyping
– Research in collaboration with industrial or other partner(s)
– “Support design while studying it”: Participatory Action Research
– Model current management of design information in the organisation – Conceptual “flat space of objects”
– Rapid prototyping approach to design application development – Iterative application deployment and testing by end users
• DRed software infrastructure solves 2 major technical problems with n-dim: – Provides sufficient level of software stability and reliability
Issue-based design in Rolls-Royce using DRed 1.0.8
• Based on Rittel’s IBIS
• Characteristic “tunnel links” • DRed 1.0.8 installed as
part of standard PLM tool set on the RR technical PC network since Q4 2005
• DRed 2.0.x releases in pilot use in RR for 1 year. Full roll out Q4 2009
• A recommended tool for 24 out of 34 steps of the RR Generic Design Practice • Problem understanding • Generation selection and
Affordance-based design (Maier and Fadel)
• Relational theory and method
– “a comprehensive high-level approach to design”
• Based on representation and deliberation of complex web of useful and
harmful relationships between:
– Artifacts, and sub-components thereof – Designers of the artifacts
– End users of the artifacts
• Chose to adopt relational concept affordance from perceptual psychology
• Authors concede that alternative relational concepts could be proposed • One such alternative concept emanated from TRIZ community, and has
been actively used in Rolls-Royce for almost a decade: Functional Analysis Diagrams (FADs)
Example of FAD modelling in Rolls-Royce
Key
Resource s
Disc Dovetail FAD
Harmful Action Component locates Primary System Function Disc Flanks Disc slot Post Disc Front Face Disc Front Arm Disc OD Blade Flanks Blade Tang Blade A/foil T/ring Rear Face Blade Rear Face Backplate T/ring Cone T/ring Disc Flange Annulus filler Chockpad retains unstresses locate stress Blade Root Neck Stress Hade Friction CF Disc Hoop Body holds locates
Blade-off
Research question
• How can comprehensible and comprehensive integrated FAD models of complex engineered systems be created, managed and linked to IBIS charts to support design?
– Needs to be able to capture and display beneficial and harmful effects acting between any pair of product structure elements, regardless of product structure hierarchy
– Note similarity to “flat space of objects” concept of n-dim
DRed 2.0.x information model
• Unlike common ontology or SysML based approaches to modelling complex engineered systems, the DRed information model:
– is as simple as possible;
– aims to be as generic as possible; – is hard coded into the software
• A major objective of the research is to supports maximum functionality of direct, immediate benefit to users with minimum perceived complexity and “learning curve”
DRed 2.0.x extension to 1.0.8 information model
FAD modelling support: blocks and relations
• Allow creation of small FADs similar to those done in PowerPoint • Block element type
– Status either internal to the system (blue fill) or external (white fill) • Relation element type
– Is a node rather than a link so relations can be many-to-many within constraints of graph formalism
– Status beneficial (green), harmful (red) or neutral (dark grey)
Large scale FAD modelling: decomposition and transclusion
• Decomposition
– Bidirectional association between a block in one file (diagram) and one or more whole other files (diagrams) defined to be decomposing it
• Transclusion
– Original hypertext concept invented by Ted Nelson in Project Xanadu – “the inclusion of part of a document into another document by reference
L the reference serving to link both documents” (Wikipedia)
– Current best known implementation is in Compendium software tool – In DRed any node can have any number of slave images of it, in the
same or other files (diagrams) each hyperlinked back to master
– Master node holds a list of its slave images, and list can be traversed round-robin style
Summary
• Shown how comprehensible, navigable large scale integrated FAD models of complex engineered systems be created, managed in software that
allows easy linking to IBIS charts to support use in design
Further work
• Upper levels of an integrated graphical functional, assembly geometry and product breakdown structure of a gas turbine have been demonstrated.
• Work is continuing on the lower levels of this decomposition, down to individual design features and parameters
• QFD2 House of Quality matrices linking functions to product elements, and other useful list and matrix views may be exported from the linked set of FADs as a useful by-product
• Work continues to optimise the user interface functionality to make hierarchical FAD modelling as easy and natural as possible for users
Thank you for listening. Any questions?
• Acknowledgements – Rolls-Royce plc – Engineering and
Physical Sciences Research Council (UK):Immortal
Information and Through-Life KM:
Strategies and Tools for the Emerging Product-Service Paradigm