A probabilistic-based design model for achieving flexibility in design

In the early stages of product development, the transformation between design requirements and design solutions often involves uncertainties when specifying the desired target value for the performance expressed in design requirements. Additionally, to provide flexibility for later development, the design solution obtained is desired to be a range rather than a single solution. Our primary focus in this paper is on developing a probabilistic-based design model as a basis for providing the flexibility that allows designs to be readily adapted to changing conditions. This is obtained by developing a range of design solutions which meet a ranged set of design requirements. Meanwhile, designers are allowed to specify the varying degree of desirability of a ranged set of design requirements based on their preferences. The Design Preference Index (DPI) is introduced as a design metric to measure the goodness of flexible designs. Providing the foundation to our work are the probabilistic representations of design performance, the application of robust design concept, and the utilization of the compromise Decision Support Problem (DSP) as a multi-objective decision model. A two-bar structural design is used as an example to demonstrate our approach. Our focus in this paper is on introducing the probabilistic-based design model and not on the results of the example problem, per se.