A Computational Framework for Authoring and Searching Product Design Specifications

Advanced Engineering Informatics
25(3), 2011

Authors: Alexander Weissman, Martin Petrov, Satyandra K. Gupta, Xenia Fiorentini, Rachuri Sudarsan, Ram Sriram

The development of product design specifications (PDS) is an important part of the product development process. Incompleteness, ambiguity, or inconsistency in the PDS can lead to problems during the design process and may require unnecessary design iterations. This generally results in increased design time and cost. Currently, in many organizations, PDS are written using word processors. Since documents written by different authors can be inconsistent in style and word choice, it is difficult to automatically search for specific requirements. Moreover, this approach does not allow the possibility of automated design verification and validation against the design requirements and specifications. In this paper, we present a computational framework and a software tool based on this framework for writing, annotating, and searching computer-interpretable PDS. Our approach allows authors to write requirement statements in natural language to be consistent with the existing authoring practice. However, using mathematical expressions, keywords from predefined taxonomies, and other metadata the author of PDS can then annotate different parts of the requirement statements. This approach provides unambiguous meaning to the information contained in PDS, and helps to eliminate mistakes later in the process when designers must interpret requirements. Our approach also enables users to construct a new PDS document from the results of the search for requirements of similar devices and in similar contexts. This capability speeds up the process of creating PDS and helps authors write more detailed documents by utilizing previous, well written PDS documents. Our approach also enables checking for internal inconsistencies in the requirement statements.


Selecting a Design-Stage Energy Estimation Approach for Manufacturing Processes

Proceedings of the ASME 2011 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference
Washington DC, August 2011

Authors: Alexander Weissman, Satyandra K. Gupta

Manufacturing is an energy-intensive process which could account for significant energy consumption worldwide. Reducing energy consumption on a product level, in addition to a process or facility level, is being seen as a more worthwhile endeavor in light of rising energy costs and environmental concerns. To accomplish this, it is necessary to consider the role of product design in energy consumption. It is possible to design a product such that its manufacture consumes less energy. However, this requires a good model of energy consumption based on the design parameters. A good model must be detailed enough to yield accurate results, but at the same time simple enough such that it can be applied easily and consistently in day-to-day design work. In this paper, we propose an approach for generating such a model by decomposing the manufacturing process into its energy-consuming components. For each component, the relevant design and manufacturing parameters can be elicited by performing sensitivity analysis through analysis and experimentation. Parameters which do not greatly contribute to variance in energy consumption can be held constant, thus simplifying the model. Thus, the simplest possible model can be derived for a specified level of accuracy. We illustrate that critical parameters from energy point of view can differ greatly from process to process by investigating representative manufacturing processes in four general categories: additive, subtractive, forming, and solidification. Finally, we present a case study for injection molding.


Energy and Power Generation Handbook: Established and Emerging Technologies. Chapter 31: Toward Energy Efficient Manufacturing Enterprises

ASME, 2011

Authors: Alexander Weissman, Kevin Lyons, Ram Sriram, Lalit Chordia
Editor: K.R. Rao

Industrial enterprises have significant negative impacts on the global environment. Collectively, from greenhouse gases to energy consumption to solid waste, they are the single largest contributor to a growing number of planet-threatening environmental problems. For example, according to the Department of Energy's Energy Information Administration, the industrial sector consumes 31% of the total energy and the transportation sector consumes 28% of the energy. Considering that a large portion of the transportation energy costs are involved in moving manufactured goods, the energy consumption of the industrial sector could reach nearly 45% of the total energy costs. Hence, it is very important to improve the energy efficiency of our manufacturing enterprises. In this chapter, we outline several different strategies for improving the energy efficiency in manufacturing enterprises. These include reducing energy consumption at the process level, reducing energy consumption at the facilities level, and improving the efficiency of the energy generation and conversion process. The main focus of this chapter is on process level energy efficiency. We present several case studies to illustrate different strategies.


A Systematic Methodology for Accurate Design-Stage Estimation for Energy Consumption for Injection Molded Parts

Proceedings of the ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference
Montreal, Quebec, Canada, August 2010

Authors: Alexander Weissman, Arvind Ananthanarayanan, Satyandra K. Gupta, Ram D. Sriram

Today's ubiquitous use of plastics in product design and manufacturing presents significant environmental and human health challenges. Injection molding, one of the most commonly used processes for making plastic products, consumes a significant amount of energy. A methodology for accurately estimating the energy consumed to injection-mold a part would enable environmentally conscious decision making during the product design. Unfortunately, only limited information is available at the design stage. Therefore, accurately estimating energy consumption before the part has gone into production can be challenging. In this paper, we describe a methodology for energy estimation that works with the limited amount of data available during the design stage, namely the CAD model of the part, the material name, and the production requirements. The methodology uses this data to estimate the parameters of the runner system and an appropriately sized molding machine. It then uses these estimates to compute the machine setup time and the cycle time required for the injection molding operation. This is done by appropriately abstracting information available from the mold flow simulation tools and analytical models that are traditionally used during the manufacturing stage. These times are then multiplied by the power consumed by the appropriately sized machine during each stage of the molding cycle to compute the estimated energy consumption per part.


Formal Representation of Product Design Specifications for Validating Product Design

Proceedings of the ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference
San Diego, California, 2009.

Authors: Alexander Weissman, Satyandra K. Gupta, Xenia Fiorentini, Rachuri Sudarsan, Ram Sriram

As collaborative efforts in electro-mechanical design have scaled to large, distributed groups working for years on a single product, an increasingly large gulf has developed between the original stated goals of the project and the final design solution. It has thus become necessary to validate the final design solution against a set of requirements to ensure that these goals have, in fact, been met. This process has become tedious for complex products with hundreds of design aspects and requirements. By formalizing the representation of requirements and the design solution, tools can be developed to a large extent automatically perform this validation. In this paper, we propose a formal approach for relating product requirements to the design solution. First, we present a formal model for representing product requirements. Then, we introduce the Core Product Model (CPM) and the Open Assembly Model (OAM) for representing the design solution. Finally, we link these models formally and provide an example with an actual consumer device.