MODIFIED GENETIC ALGORITHM APPLIED TO SOLVE PRODUCT FAMILY OPTIMIZATION PROBLEM

The product family design problem solved by evolutionary algorithms is discussed. A successful product family design method should achieve an optimal tradeoff among a set of competing objectives, which involves maximizing commonality across the family of products and optimizing the performances of each product in the family. A 2-level chromosome structured genetic algorithm （2LCGA） is proposed to solve this class of problems and its performance is analyzed in comparing its results with those obtained with other methods. By interpreting the chromosome as a 2-level linear structure, the variable commonality genetic algorithm （GA） is constructed to vary the amount of platform commonality and automatically searches across varying levels of commonality for the platform while trying to resolve the tradeoff between commonality and individual product performance within the product family during optimization process. By incorporating a commonality assessing index to the problem formulation, the 2LCGA optimize the product platform and its corresponding family of products in a single stage, which can yield improvements in the overall performance of the product family compared with two-stage approaches （the first stage involves determining the best settings for the platform variables and values of unique variables are found for each product in the second stage）. The scope of the algorithm is also expanded by introducing a classification mechanism to allow mul- tiple platforms to be considered during product family optimization, offering opportunities for superior overall design by more efficacious tradeoffs between commonality and performance. The effectiveness of 2LCGA is demonstrated through the design of a family of universal electric motors and comparison against previous results.

Study on an Configuration Framework for Product Family

In implementing mass customization, how to respond rapidly to customers’ requirements is a key problem. Configuration design is considered effective in early stage of product design. This paper studies a configuration method based on constraints and fuzzy decision for product family. The configuration method is evolved from constraint based product configuration. It employs fuzzy optimum selection in the reasoning process, which can select similar components when customers’ requirements can not be met precisely. In the configurator, product family is represented with GBOM(Generic Bill Of Material) and ACL(Article Characteristic List). Every node of GBOM has an ACL to list all instances of a component family. Constraints are attached to every node, which involves variable definition and constraints definition. In the reasoning process, constraint satisfaction and fuzzy optimum selection interact to search optimum solution. A prototype is developted to demonstrate how to run the configurator. The paper ends with a discussion of advantages, future work of the configuration method.

A Case Retrieval Projection Pursuit Model for Configuration Design of a Product Family

The paper studies on case-based reasoning of uncertain product attributes in configuration design of a product family. Interval numbers characterize uncertain product attributes. By interpolating a number of certain values randomly to replace interval numbers and making projection pursuit analysis on source cases and target cases of expanded numbers, we can get a projection value in the optimal projection direction. Based on projection value, we can construct a case retrieval model of projection pursuit that can handle coexisting certain and uncertain product attributes. The application examples of chainsaw configuration design show that case retrieval is highly sensitive to reliable results.

Supporting Product Family Design in a3D CAD/PDM Integrated System

This paper addresses some key issues in supporting product family design in a 3 D CAD/ PDM integrated system and introduces the techniques developed or adopted in building the integrated system. The general architecture of a 3D CAD/PDM integrated system is organized as five tiers. Multi-agent technology is applied with a collaborative design environment. The rule-based product family architecture （ PFA ） and tabular layouts of article characteristics （TLAC） technique are applied to represent the knowledge for product families. They make the knowledge understandable, simplified and can be exchanged among heterogeneous information systems. A transparently concentric integrated mode is put forward to enable the heterogeneous processes to interact and communicate regardless of the language used to construct each process. With the mode, function calling and information exchanging among different processes are carried out via message translation/parse approach. Currently, the integrated system is implemented in the platform of Windows NT and 2000.

Product Family Design Methodology Using Object-Oriented Approach

The serious competition environment of global marke t requests the enterprise to change traditional product development strategy and a dopt new theory in order to meet diverse customer needs while maintaining near m ass production efficiency, which is the main philosophy of mass customization. P roduct family design is research focus at present and also is the core technolog y of DFMC (design for mass customization). Firstly, this paper explores the fund amental issues of product family, such as concepts of modularity, commonality/di versity, product platform and product family architecture etc. We compare the te rminology between product family and object-oriented approach in the next step. Thirdly, this paper puts forwards one product family design methodology based o n product platform and under different phase of product life cycle constrains, f or example, functional, assembly and service etc. At the end section of this pap er, we applied, the object-oriented approach in above mentioned product family design methodology to realize the design process. In one word, this paper propos ed one product family design methodology based on object oriented approach and p roduct life cycle consideration, especially the conjointness of characteristic o f OOA and concepts of product family. The main property of OOA are encapsulation , inherence and polymorphism. Encapsulation can represent the module or building blocks of product family. Inherence can be extended to describe the modularity and commonality, and also be used to construct variant space. Alternative specif ic of product family architecture can be embodied with polymorphism. And fin aly, we give the future work contents. In order to derive the product platform a nd achieve modularity and commonality/diversity, interface management between bu ilding block is necessary. The question is how the OOA can be applied in interfa ce management to get our aim OOA is the basis of many information management sy stem, then the question is how to build one system to manage the information of product family and support mass customization The third question is how to deve lop one computer aided tool to facilitate the application of OOA for product fam ily design, even be used to category of design for mass customization.

Markov Chain for Reuse Strategies of Product Families

A methodology is presented to plan reuse strategies of common modules in a product family by using the concepts of function degradation, reliability, function requirement, cost and life time. Markov chain model is employed to predict function degradation and reliability. A utility model is used to evaluate the preference between used modules and new modules. An example of cascading-requirment product family illustrates the main ideas of our work. The Markov models are used effectively to predict function degradation and reliability. Utility theory is helpful to evaluate the reuse options of common modules.