Examining multiple alternatives during the styling activity is an example of set-based concurrent engineering. Toyota considers a broad range of alternatives and systematically narrows the sets to a final, often superior, choice.
Set-based concurrent engineering considers the different design perspectives proposed by different parties, a phenomenon that can best be graphically illustrated by Venn diagrams. Each party has some acceptable range of alternatives – a solution space that will work from its own perspective. Front-loading finds where the sets overlap and, in the process, identifies the winning design solution.
Toyota’s approach has essentially eliminated a great deal of waste while achieving a superior solution.
Toyota’s process does not focus on the speedy completion of individual component designs in isolation, but instead looks at how individual designs will interact within a system before the design is compete. In other words, they focus on system compatibility before individual design completion. The principle of compatibility before completion is fundamental to the set-based approach and is a major contributor (along with standard architecture and processes) to Toyota’s extremely low number of engineering changes.[singlepic id=27 w=320 h=240 float=center]
To get at the root of “set-based thinking”, however, requires an understanding that it is more than a specific set of tools or methods. Companies can adapt structural aspects of this culture to their own PD by using the following:
- Intentionally identifying multiple solutions to design problems before selecting just one.
- Encouraging engineers (both upstream and downstream) to discuss alternatives early before a fixed decision has been reached on a single design from one perspective.
- Using set-based tools such as trade-off curves to identify the trade-offs of various solutions from different perspectives.
- Capturing past knowledge in checklists in the form of graphs and equations that show the effects of different alternatives.
- Using system methods like parametric design that quickly show system impacts when parameters are changed.
- Having structured time early in this front-end period for participants with diverse perspectives to work out solutions when the broadest set of alternatives is still available.
Source: Liker, J.K and Morgan, J.M, The Toyota Product Development System: Integrating People, Process and Technology, Productivity Press, 2006