Product Development Lead-time Research Articles

Research on Control Strategy of Design Change Cross-Module Propagation

In the process of product design, design changes are unavoidable due to the diversification of customer requirements and the advancement of key technologies. Although modules are supposed to be functionally independent and “low-coupling” in modular products, the design change in a module can still propagate into other modules due to the interfaces among them, and this propagation increases the product development lead-time and costs. This study aims to solve the problem of cross-module propagation in design change. First, the dependence of modules on interfaces is analyzed from the perspectives of complex network characteristics, change propagation characteristics, and cost dependence, and then the correlation between modules is determined. Second, the cross-module change propagation impact is evaluated considering node importance, change cost, and propagation path length. The control strategies of cross-module design change propagation are proposed from the aspects of increasing the tolerance of interface and reducing the dependence of modules on interface, etc. Finally, a certain type of sanitation vehicle cab is utilized as an example to demonstrate the assessment process of the cross-module propagation impact of design change and to verify the feasibility of the proposed method and control strategies.

Response Surface Methodology (RSM) Optimization of the Batch Process in a Rectangular Passive Greenhouse Dryer

The prototyping of dryer design and performance by application of the trial-and-error technique in one-factor-at-a-time (OFAT) testing is completely arbitrary, expensive and time consuming. Reducing product development lead-time and cost while concurrently improving customer satisfaction for a good manufacturer enhance rapid response to market demand which is a highly effective way of improving returns on investment. In this study a numerical model for the digital prototyping of the rectangular passive greenhouse dryer design and the optimization of the batch process in the solar dryer was developed. An interactive, user-friendly computer package ANSYS 14.0 was used to develop an empirical model. The package was used among others, for the response surface methodology (RSM) optimization to specify the dryer parameters that maximize the dryer mean temperature. The factorial experiments in a central composite design (CCD) revealed that only the inlet vent dimensions influence the mean temperature within the greenhouse dryer. The parametric analysis for robust design yielded the inlet vent height of 0.27m and inlet vent width of 0.45m as the optimum design variables that maximize the mean temperature of the drying air as 320.48K (47.30 °C). The numerical approach established facilitated the prototyping and optimization of the batch process in the passive greenhouse dryer.The prototyping of dryer design and performance by application of the trial-and-error technique in one-factor-at-a-time (OFAT) testing is completely arbitrary, expensive and time consuming. Reducing product development lead-time and cost while concurrently improving customer satisfaction for a good manufacturer enhance rapid response to market demand which is a highly effective way of improving returns on investment. In this study a numerical model for the digital prototyping of a rectangular passive greenhouse dryer design and the optimization of the batch process in the solar dryer was developed. Multiple regression was used as the data-analytic system for the factorial experiment to develop an empirical model, predict the response variable and then test hypothesis in an interactive, user-friendly computer package ANSYS 14.0. The package was further used for the response surface methodology (RSM) optimization to specify the dryer parameters that maximize the dryer mean temperature. The factorial experiments in a central composite design (CCD) revealed that only the inlet vent dimensions influence the mean temperature within the dryer. Appraisal of the model through the coefficient of determination ( =0.99973) showed that the model can account for 99.973% variability observed in the dryer mean temperature consequently, the suitability of RSM for the analysis of the dryer variables. The parametric analysis for robust design yielded the inlet vent height of 0.27m and inlet vent width of 0.45m as the optimum design variables that maximize the mean temperature of the drying air as 320.48K (47.30°C). The numerical approach established facilitated the prototyping and optimization of the batch process in the passive dryer.

Investigation of mechanical properties and form error of the components fabricated by rapid prototyping: A review

3D printing is emerging as one of the most important and advanced technique of manufacturing. Nowadays, manufacturing industries is focusing on reduction of lead time of product development and cost of product. 3D printing has large application in many fields such as aerospace and defence, medical, consumer goods etc .The purpose of this study was to present a concise review on rapid manufacturing processes. This paper includes historical development, available technologies, materials and their tangible benefits. Researchers have analyzes the influence of process parameters like orientation, layer thickness, air gap, printing direction etc. on properties of components which are fabricated through 3D printing. The noble contribution of this paper is to present systematic approach to enable potential for academics user as well as industry persons to select appropriate technology.

Feasibility analysis of manufacturing using rapid prototyping: A review

Nowadays manufacturing industries is focusing on reduction of lead time of product development and cost of product. Rapid prototyping has become a solution to manufacturing industry globally. The purpose of this study is to present a concise review on rapid manufacturing processes. This paper includes historical development, available technologies, materials and their tangible benefits. The noble contribution of this paper is to present systematic approach to enable potential for academics user as well as industry persons to select appropriate technology.

Faster or fewer iterations? A strategic perspective of a sequential product development project

Shortening the lead time for Product Development (PD) provides enterprises with a competitive advantage. Given the iterative nature of PD projects, two aspects are regularly considered to shorten the PD lead time, that is, conducting faster or fewer iterations. However, executing faster iterations usually causes more iterations and vice versa. Therefore, suitable coordination between faster and fewer iterations is necessary to minimize the PD lead time. We investigate this coordination from a strategic perspective, whereby a PD project is considered as a sequence of stages and characterized by the design rates and rework probabilities of those stages. We model the coordination as a decision to choose the appropriate design rates for each stage, wherein the rework probabilities are negatively related to the design rates. An absorbing Markov process is applied to calculate the expected lead time of a PD project. Further, we formulate a geometric programming model to determine the optimal design rates of the stages with respect to the minimal expected lead time. Several insights are extracted from the model to provide general guidance on the coordination, including the effect of the acceptance check rate of the project, rework risk of the stages on the optimal design rates, and decomposability of the coordination. Inspired by these insights, an efficient heuristic algorithm is designed. The algorithm performs well in numerical experiments, which in turn validates the insights. Additionally, a field case proves the effectiveness of our model. Compared with the current policy, 12.25% of the PD lead time is saved through appropriate coordination between faster and fewer iterations.

Fabrication of prototype connecting rod of PLA plastic material using FDM prototype technology

Rapid prototyping (RP) have been attracting attention in the manufacturing community because of their capability to reduce the lead time of product development. Present work is an effort to understand the influence of process variables like infill pattern, layer thickness, build orientation and infill density on dimensional accuracy (DA), flatness and cylindricity. Taguchi method orthogonal array L9 was used for the conduction of experiments. MakerBot Replicator-2 was used for the fabrication of scaled prototype connecting rod of polylactic acid (PLA) material. DA, flatness and cylindricity of the component were measured by using coordinate measuring machine (CMM). Analysis of variance (ANOVA) was employed to find out the significance of process parameters. A regression model was developed to predict the DA, flatness and cylindricity. The results reveal that the optimum process parameters for the DA, flatness and cylindricity were different. Utility Theory was used to find out the best process parameter condition. The best process parameters for the DA, flatness and cylindricity was found to be layer thickness 100 μm, linear infill pattern, inclined at 45ºorientation and 20% infill density. A confirmation test was conducted for checking the goodness of the model, which reveals that results were within the confidence limit.

Drivers and Guidelines in Design for Qualification Using Additive Manufacturing in Space Applications

AbstractIn recent years, reducing cost and lead time in product development and qualification has become decisive to stay competitive in the space industry. Introducing Additive Manufacturing (AM) could potentially be beneficial from this perspective, but high demands on product reliability and lack of knowledge about AM processes make implementation challenging. Traditional approaches to qualification are too expensive if AM is to be used for critical applications in the near future. One alternative approach is to consider qualification as a design factor in the early phases of product development, potentially reducing cost and lead time for development and qualification as products are designed to be qualified. The presented study has identified factors that drive qualification activities in the space industry and these “qualification drivers” serve as a baseline for a set of proposed strategies for developing “Design for Qualification” guidelines for AM components. The explicit aim of these guidelines is to develop products that can be qualified, as well as appropriate qualification logics. The presented results provide a knowledge-base for the future development of such guidelines.

Multilevel optimisation method for vehicle body in conceptual design

Since product development lead-time needs to be as short as possible in contemporary enterprises, it is necessary to assess and optimise the performance of the structure in conceptual design phase for avoiding the time consuming production of trial models for vehicle body. This paper proposes a conceptual design tool based on optimisation algorithms for global body frames named vehicle concept design-intelligent CAE system (VCD-ICAE). A multilevel optimisation algorithm is applied to optimise the body performance, to decide the size parameters and generate cross-sectional shapes that satisfy design engineers' required characteristics. The global body stiffness and vibration property would be optimised while decreasing the mass of body. The paper describes the implementation of the optimal algorithm, and genetic algorithms are applied to solve the optimisation problem. A case of optimisation for a real car is given to verify the validity of the algorithm.

Multilevel optimisation method for vehicle body in conceptual design

Since product development lead-time needs to be as short as possible in contemporary enterprises, it is necessary to assess and optimise the performance of the structure in conceptual design phase for avoiding the time consuming production of trial models for vehicle body. This paper proposes a conceptual design tool based on optimisation algorithms for global body frames named vehicle concept design-intelligent CAE system (VCD-ICAE). A multilevel optimisation algorithm is applied to optimise the body performance, to decide the size parameters and generate cross-sectional shapes that satisfy design engineers' required characteristics. The global body stiffness and vibration property would be optimised while decreasing the mass of body. The paper describes the implementation of the optimal algorithm, and genetic algorithms are applied to solve the optimisation problem. A case of optimisation for a real car is given to verify the validity of the algorithm.

A Proposed Technology Platform Framework to Support Technology Reuse

Managing a technology portfolio is one of the great challenges for sustained success, especially in high-technology industries where technologies can be a major selling point. For engineers, this portfolio is more of a toolbox for solving design problems, but in large organizations there can be so many technologies used in different business areas that even the engineers may not be aware of all of them. When the same technologies are used in different types of products, knowledge about them can also be generated by various groups within an organization. To improve the usefulness of a company's technology base, this paper proposes the use of a technology platform approach based on a framework featuring three different types of activities. The first approach is about adapting the technology base to future needs with the help of portfolio management techniques. The second approach serves to create awareness and shared understanding through an interactive technology catalogue, collecting information about how technologies work, where they are applied, and how they are used. The third approach is addressed at engineers who work with the technologies and includes practices for improving the reusability of knowledge recorded in documents and communicated to others who are using a particular technology for development. The framework is intended to support a systematic approach for technology reuse in order to stimulate organizational learning and reduce lead-time and cost of product development.

1410 ID-CAEと3D-CAEを使い分けた制御盤設計検証技術

As increasing the computational power, large scale 3D analysis become more routine to estimate the performance in thermal and earthquake resistant design on control console system. We also developed a ID CAE tools using simple formula to realize First Order Analysis in early design stages. However, it takes a lot more than conventional optimization design method to meet a recent product development lead-time. So it is necessary to develop a new mechanical design method suited for innovative product development. Therefore, we propose a new design process concept in reference to knowledge development process "SECI model". SECI model is composed of Socialization, Externalization, Combination, and Internalization. So we apply the SECI model framework to our real development process using ID-CAE and 3D-CAE. As a result, our first attempt was validated reasonably and developed a new control console structure was build with decreasing by half in setting area.

A Methodology for Product Performance Analysis under Effects of Multi-physical Phenomena

Due to the development of science and technology, the computer has become a useful tool for supporting engineering activities in product design. Many computer aided tools such as Computer Aided Design/Manufacturing (CAD/CAM), product data management (PDM), product life cycle assessment (PLA), etc., have been popularly used in industry for reducing product development leadtime and increasing total product quality. As a result, product designers can easily create the numerical model of product based on these tools. However, it can only represent nominal information of the product. It is not able to deal with various kinds of multi-physical effect during the whole product life cycle, especially in manufacturing/assembly and product usage stage. Performance analysis of product based on this model gives a result that is different from the real product in practice. It can make the quality of the product designed not to meet fully the requirements of customers and users. Thus, this paper proposes a global methodology that allows integrating the multi-physical effect throughout the product life cycle into the performance simulation. The variation sources throughout product life cycle are taken into account performance analysis of product.

Decision support tool for lean product and process development

Lean and concurrent engineering (CE) are widely acknowledged business process improvement strategies. These strategies can improve processes, reduce costs, and cut waste enabling organisations to remain competitive. Lean manufacturing offers an enterprise-wide methodology that improves reliability and flexibility while reducing lead-times and inventory carrying costs. Companies in manufacturing and service sectors are focusing on integrating lean manufacturing methodology with other applications, so that, all their systems and processes are aligned. This article proposes a CE framework based on application of information technology and object-oriented methodology for lean manufacturing. This approach expected to give manufacturing companies an extra edge in today's competitive market. A case study is presented in this article to demonstrate the effectiveness of CE framework in a machine tool manufacturing company. CE practice was adopted for new products, to align the systems and processes of the company. Product development lead-time was found to decrease by more than 50% compared to similar development projects carried out by the company. The need for rework was found to be negligible and the development cost was reduced considerably.

A design representation scheme for collaborative product development

Design is an integral component of product development, which includes manufacturing. In order to avoid costly reworks and delays, and to reduce the lead-time in product development, effective communication of design concepts among the various stakeholders such as customers, designers and engineers is of utmost importance. In this respect, functional representations provide a methodology, which can be used to describe a design or product effectively. However, function is not the only type of information that needs to be communicated among the various stakeholders during a design process. Other types of information such as design specifications and constraints, which are non-functional, also need to be taken into account. This non-functional information cannot be adequately expressed using existing functional representations. Accordingly, in this work, a novel purpose-behaviour-structure (PBS) representation scheme to capture vital design knowledge for collaborative product development is proposed. The proposed PBS representation scheme can be used by designers working in a collaborative environment for product development. A case study on the design of a vacuum cleaner is used to illustrate the functionality of the PBS representation scheme. The details of the representation scheme are presented in this paper.

New product development process and time-to-market in the generic pharmaceutical industry

Generic pharmaceutical companies tend to improve their market position by being first in the market when a patent on an original product elapses. The time-to-market of new products is an important source of their comparative advantages. In our study we investigate the organizational and managerial factors lying behind time-to-market in four generic pharmaceutical companies in Central and Eastern Europe. Our research also supports some results found in other studies on the lead-time of new product development. However, we find some factors specific to generic pharmaceutical companies. Our findings are incorporated into a diagnostic model of new product development in generic pharmaceutical companies, which is an important practical result of our research.

A Cross-sectional Shape Initial Design Method for Automotive Frame Structure Using Genetic Algorithms

As CAE (Computer Aided Engineering) applications become increasingly precise, the knowledge and technical skill required to operate such application has become more highly specialized. Such tools have not been utilized in the initial design process of mechanical products, where designers cannot construct detailed analytical models. This paper proposes a cross-sectional shape design optimization system that supports the initial design process for automotive frame structures. The cross-sectional design problem is formulated as a multiobjective optimization problem that can be solved using genetic algorithms. A method for generating cross-sectional shapes satisfying designer-required characteristics is also proposed. These methods, which reduce the number of trial and error process and product design failures, are expected to enable shortened product development leadtimes.

109 機械構造の初期設計 : GA を用いた断面形状の最適化

As CAE (Computer Aided Engineering) applications become increasingly precise, the knowledge required to operate these application are highly specialized. These tools have not been utilized in initial design process of mechanical products, in which designers cannot construct detailed analysis models. This paper proposed design optimization system a cross-sectional shape that can support the initial design process of bar structure. The cross-sectional design problem is formulated as a eight-objective optimization problem which can be solved using genetic algorithms. A method to generate a shape of cross-section satisfying characteristics that required by a designer is also proposed. These methods, which can reduce the number of trial and error process and failure in product design, are expected to contribute shortening product development lead-time.

Managerial issues in parts sharing among product development projects: a case study

Sharing parts across a set of products has long been considered good design practice but now, it is also considered as a strategic weapon in many industries. Earlier research has singled out parts sharing as an important means of shortening the product development lead-time, reduce cost and increase product quality. Moreover, companies are striving towards reaching efficient parts sharing. However, commonality trends in several industries show that they have trouble reaching their commonality targets. Hence, the aim of this case study is to explore the potential managerial difficulties associated with the parts sharing process. Six manufacturing companies in four different industries have been explored. The managerial difficulties have been divided into four categories, namely organizational, strategic, technology & cost related, and support system related issues. Summarizing the findings, the task of transferring parts has proved to be a complex issue with many cross-boundaries and managerial concerns within the company, and the responsibilities need to be made clear.

Integrated and concurrent approach for compound sheet metal cutting and punching

In sheet metal processing and manufacturing, there are a lot of small- and medium-sized job shops. These small- and medium-sized manufacturing companies have been facing keen competitive pressure in the market. This pressure has forced these companies to make every effort to shorten product development lead-time, improve production efficiency, approach high-quality standards, but at the same time cut down the costs. To meet the needs of these companies, this paper presents a compound cutting and punching production method supported by an integrated CAD/CAPP/CAM system in sheet metal manufacturing. Many existing commercial CAD/CAM systems are not suitable for this manufacturing method, especially under concurrent and global design and manufacturing environments. Some problems have to be solved before these CAD/CAM systems can be employed and integrated for this compound manufacturing method. This paper deals mainly with the solutions to solve some of these problems. The solutions include an integrated data integration platform based on Pro/INTRALINK and STEP, and a knowledge-based real time CAPP (RTCAPP) system for compound sheet metal cutting and punching. Within the presented CAD/CAPP/CAM system, some key modules have been developed. They are the automatic tool selection and manufacturing sequencing module, a shortest tool path optimization module, a cost estimation module and an automatic insertion of auxiliary path module based on knowledge bases. These modules will be addressed here.

DESIGN OPTIMIZATION OF A COMPLEX MECHANICAL SYSTEM USING ADAPTIVE RESPONSE SURFACE METHOD

Today’s increasingly competitive industrial environment demands shorter product development lead-times, lower costs, and higher quality products. These requirements produce more complex design prob...