Colouring the path to design success

s Arguments and justifications leading to design decisions are captured in a totally new approach that mimics brainstorming sessions using whiteboards and ‘Post it’ notes – but makes the whole process accessible to all who might benefit. Developed and in service, although still being enhanced, the idea comes out of joint research undertaken by Rolls Royce and the Cambridge Engineering Design Centre. The method ensures that it is no longer possible – with the benefit of hindsight – to edit accounts of how right and wrong decisions were reached. At the same time, experience-based knowledge leading to right decisions will be captured for the benefit of future designers in a way that can be seen instantly. According to Professor Ken Wallace, who began his career as a Rolls Royce apprentice, research shows that searches for information seldom refer to documents. “About 90% of information comes from colleagues and 80% comes from somebody’s memory,” he said at a recent seminar in Cambridge on ‘Improving the Design Process’. He cited reasons for preferring to ask colleagues as speed, context, query evolution, ready availability from memory and trust and confidence, but asked: “What happens when they [their colleagues] are no longer there?” In the past, engineers often remained with one company throughout their careers, but now they were much more likely to move jobs – leading to a constant loss of expert knowledge. This has led to the development of ‘Dred’ – Design Rationale editor – which has been rolled out to 600 Rolls Royce engineering designers in Derby, Bristol, Dahlewitz and Montreal, via a two and a half hour course, and has been made mandatory for all design reviews. Dr Rob Bracewell, who also associated with the Engineering Design Centre, has been leading the venture and demonstrated its use of graphical icons, coloured to indicate status, which are associated with short statements and linked by arrows. The icons are referred to as ‘elements’ and come in different forms, according to whether they represent issues, requirements, answers or arguments. When first placed on the chart, ‘Issue’ and ‘Answer’ icons are amber. If accepted by the relevant designer, they are turned green; if rejected, they are turned red. Arguments are coded ‘green’ for pro and ‘red’ for con. Abandoned ideas get greyed, but are still retained by the system, should anyone want to go back and look at why they were rejected. “The charts can appear a bit messy,” Bracewell admitted, “but a single chart is the equivalent of 10 pages in a designer’s notebook. It is important that human designers follow the arrows, so we are not going to make propagating status changes automatic.” An important goal of the project is to ensure that no extra burden is place on hard-pressed designers, he added. Because major design projects involve many issues, chart pages can be linked to other pages by bi-directional tunnel links. Meanwhile, research and development is focused on linking to external documents, with the initial spotlight on Microsoft Office types, based on standard MS Office bookmarks and hyperlinks. Linked documents include Excel spreadsheets and designs in 3D CAD tools such as Autodesk Inventor, images that can be auto updated when source files change, and files stored in a change-tracked depository, such as Autodesk Vault. Rolls Royce is actively investigating offering the solution commercially, states Bracewell. Interested parties should email: technology.licensing@rolls-royce.com Pointers * Process consists of charts of notes that record ideas and arguments * The charts capture both accepted and rejected design solutions, and their supporting arguments and dependencies * An important goal of the project is that it places no extra burden on hard-pressed designers