Figure 5 - uploaded by Janet Allen
Content may be subject to copyright.
Source publication
How can the manufacturability of different product design alternatives be evaluated efficiently during the early stages of concept exploration? The benefits of such integrated product and manufacturing process design are widely recognized and include faster time to market, reduced development costs and production costs, and increased product qualit...
Contexts in source publication
Context 1
... Our proposed method for robust product and process exploration is shown in Figure 5. As a product-independent task, Step 1 is creating response surface models for each machine (or perhaps each machine class) on the shop floor. ...
Context 2
... on the machining center example described in the previous section, we now walk through the steps of the RCEM. Sections 4.2.1 through 4.2.3 illustrate Step 1 of our method shown in Figure 5, and Section 4.2.4 begins to delve into the product/process trade-offs of Step 5 of our method, which is continued in Section 4.3. ...
Citations
... The literature on using surrogate models on systems instead of components, as well as surrogate models as a tool of analysis, is more rare. One example of the earlier is [6], while an example of the latter can be found in [7] who study fault detection in robotics. ...
... Many approaches exist for modeling uncertainty in design (Thurston, 1990;Allen et al., 1992;Otto and Antonsson, 1993;Chen et al., 1996;Peplinski et al., 1996;Hazelrigg, 1998). We apply probability mathematics in this paper, reflecting the fact that the uncertain factors covered in this analysis are not due to designer preference uncertainty, but uncontrollable factors during the development and operation of the products. ...
A platform is the set of elements and interfaces that are common to a family of products. In this paper, the design of a platform-based product family is formulated as an optimization problem. This optimization is then transformed into a two-step process amenable to industrial product design processes. The first step involves designing the technical aspects of the product family, optimizing an objective (or a set of objectives) subject to technical constraints, with external uncertain factors fixed. We have previously presented such a method for designing product families based on platforms that optimizes performance and cost metrics, using variables and a system model. That approach allows a team of engineers to design and evaluate candidate platforms, given perfect understanding of the designs and requirements. The second step is to quantify the value to the firm for each identified design alternative, while here accounting for external uncertain factors of the product family development. In this paper we present a model to perform this second step of the overall approach. Real options concepts are introduced to model the risks and delayed decision benefits present during product development due to uncertainty in technologies, funding, etc. We develop a quantitative measure of the value to the company for different family designs, and apply it to select the most appropriate design from the possible alternatives. An application to the design of platform-based families of spacecraft is shown.
... The RCEM approach has been tested for various engineering design problems (Chen et al. 1997;Simpson et al. 1996;Koch et al. 1996;Peplinski et al. 1996;Lautenschlager et al. 1996;Bailey et al., 1997). These preliminary studies of the RCEM illustrated that the RCEM can be used to greatly enhance the optimization capability and facilitate fast convergence of the solution for designs involving high fidelity analysis. ...
A systematic and affordable approach is proposed for the robust design of thick laminated composite structures. Our approach integrates the principles of the Robust Concept Exploration Method (RCEM) for designing complex engineering systems and the hierarchical multi-level optimization procedure for managing the complexity of composite structure optimization. Foundational to the proposed approach is the use of Design of Experiments (DOE) techniques and the Response Surface Methodology (RSM) for improving computational efficiency in using high fidelity design simulations; and the use of the robust design method for improving the quality of a product that is insensitive to potential variations of design parameters. Our approach is illustrated through the design of a laminated composite femoral component for hip joint arthroplasty. The solution yields the robust design of a composite hip implant, which is applicable for a range of bone stiffness, thereby eliminating the need to design specifically for an individual.
... The robust design concept (Phadke, 1989) is utilized to determine specifications that are robust, i.e., insensitive to adjustments in later stages of design or during operation, and flexible, i.e., allowed to vary within a range. RCEM has been tested for various engineering design problems ( Simpson et al., 1996; Koch et al., 1996; Peplinski et al., 1996; Lautenschlager et al., 1996; Bailey et al., 1997). The type of analysis (simulation) programs used in these applications ranges from airframe and propulsion analyses in aircraft design, engine thermodynamic analysis, and finite element structural analysis, to manufacturing systems analysis. ...
In this article, a robust design procedure is applied to achieve improved vehicle handling performance as an integral part of simulation-based vehicle design. Recent developments in the field of robust design optimization and the techniques for creating global approximations of design behaviors are applied to improve the computational efficiency of robust vehicle design built upon sophisticated vehicle dynamic simulations. Our approach is applied to the design of a M916A1 6-wheel tractor / M870A2 3-axle semi-trailer. The results illustrate that the proposed procedure is effective for preventing the rollover of ground vehicles as well as for identifying a design that is not only optimal against the worst maneuver condition but is also robust with respect to a range of maneuver inputs. Furthermore, a comparison is made between a statistical approach and a bi-level optimization approach in terms of their effectiveness in solving robust design problems. NOMENCLATURE x Vec...
... The RCEM approach has been tested for various engineering design problems [3][4][5][6][7][8]. ...
Improvements in industrial productivity require the creation of a reliable design in the shortest possible time. This is especially significant for designs that involve computer intensive analyses. The Robust Concept Exploration Method (RCEM) embodies a systematic approach to configuring complex engineering systems in the early stages of product design by introducing quality considerations based on the robust design principle. Approximation techniques are employed in the RCEM to replace intensive analysis programs for saving the computational time and cost, thereby increasing the efficiency of a design process. In this paper, the applicability of the RCEM for multiobjective complex systems design is examined by applying it to the propulsion system conceptual design process at Pratt & Whitney. Various approximation techniques are studied and a new strategy is proposed to enhance the existing model approximation techniques embodied in the RCEM. Key Words: Concept Evaluation, Model Appro...
... Foundational to the RCEM is the integration of robust design principles, design of experiments and response surface methodology, and the compromise Decision Support Problem (DSP) (a multiobjective decision model which is a hybrid formulation based on Mathematical Programming and Goal Programming). This RCEM is applied to a High Speed Civil Transport (HSCT) in (Chen, et al., 1996a) The authors of this paper have also applied RCEM to the design of a General Aviation Aircraft (Simpson, et al., 1996), to a manufacturing simulation problem (Peplinski, et al., 1996), and to the design of a turbine lift engine (Koch, et al., 1996). NORMAN/DEBORA is a TCAD (Technology Computer Aided Design) system created by a Belgian company, IMEC, incorporating advanced sequential design of experiments (DOE) and Response Surface Methodology (RSM) techniques to aid in engineering optimization and robust design problems. ...
Perhaps the most prevalent use of statistics in engineering design is through Taguchi's parameter and robust design -- using orthogonal arrays to compute signal-to-noise ratios in a process of design improvement. In our view, however, there is an equally exciting use of statistics in design that could become just as prevalent: it is the concept of metamodeling whereby statistical models are built to approximate detailed computer analysis codes. Although computers continue to get faster, analysis codes always seem to keep pace so that their computational time remains non-trivial. Through metamodeling, approximations of these codes are built that are orders of magnitude cheaper to run. These metamodels can then be linked to optimization routines for fast analysis, or they can serve as a bridge for integrating analysis codes across different domains. In this paper we first review metamodeling techniques that encompass design of experiments, response surface methodology, Taguchi methods, neural networks, inductive learning, and kriging. We discuss their existing applications in engineering design and then address the dangers of applying traditional statistical techniques to approximate deterministic computer analysis codes. We conclude with recommendations for the appropriate use of metamodeling techniques in given situations and how common pitfalls can be avoided.
... • endogenous factors such as design risks, outcomes of tests during development, or new technologies, and • exogenous factors, such as funding changes, market acceptance of the product, etc. Many approaches exist for modeling such uncertainty [1,4,19,20,28]. We apply probability mathematics in this paper, reflecting the fact that these uncertainties are not due to designer selection uncertainty, but uncontrollable factors. ...
A platform is the set of elements and interfaces that are common to a family of products. We have previously presented a method for designing product families based on platforms that quantifies performance and cost metrics. That approach allows a team of engineers to design and evaluate candidate platforms, given perfect understanding of the designs and requirements. In this paper we present a model to account for uncertainty present during the development of those product families. Real options concepts are introduced to model the risks and delayed decision benefits present under uncertainty in technologies, funding, etc. We develop a quantitative measure of the value to the company for different family designs, and apply it to select the most appropriate design from the possible alternatives. An application to the design of platform-based families of spacecraft is shown. Results from the models indicated the platforms that were most valuable to the company under different scenarios, ...
... However, it must be remembered that it does so by changing the characteristic of the original problem. Karandikar and Mistree (1993) and Peplinski, et al. (1996) have already shown that the Compromise DSP is an adequate tool to support the integration of enterprise design processes. ...
Information gathering and refinement are critical activities in conceptual design. A decision-based framework is developed consisting of three main components: a flexible, extensible design space model based on a Gaussian kernel which synthesizes information from design instances; expected value decision- making which focuses the design process on the most promising subspaces within this model; and information value theory which identifies uncertainty in the design evaluation whose reduction could redirect the design process. Together, these components form a normative method for conceptual design around a key process - the co-evolution of a design and the evaluation model used to quantify its value. Formalizing conceptual design toward reducing arbitrary design decisions and focusing attention on the most critical design concerns holds the potential to substantially improve both the process and product of design. The proposed methodology is demonstrated through an example in the domain of electric motor selection.
The effectiveness of manufacturing enterprises that compete with product families can be leveraged through an appropriate standardization of components. In this paper we exam- ine how a robust standardization of components can be implemented in the early stages of design with an explicit evaluation of the production system. The approach is based on (1) a mathematical formulation of design decisions using the Compromise Decision Support Problem (DSP), which includes robustness considerations, and (2) modeling production systems as networks of response surfaces. This modeling method facilitates evaluation of the impact of product design changes on the performance of the production system, thus enabling concurrent product-process design exploration. We demonstrate the approach with a case study, namely, the design of an absorber-evaporator module for a family of absorption chillers. @DOI: 10.1115/1.1359786#
