Y. L. Tu

An information system for one-of-a-kind production

Small and medium sized enterprises (SMEs) need to find ways of maintaining their competitive advantages of high customization, short lead time and high quality and overcoming high production cost because of growing competition from large global mass producers. To maintain and enhance these advantages and in the meantime to keep the production efficiency and reduce production cost requires SMEs to move to mass customization which is supported by various computer aided engineering, manufacture and management technologies or digital manufacturing technologies, such as computer aided design (CAD), process planning (CAPP), and manufacturing (CAM). However, for efficiently producing one-of-a-kind products by using one-piece flow production methods, accurate and timely information is required in large quantities which need to be processed by an information system. This paper presents the development of such an information system, which enables a medium-sized window and door manufacturer in Calgary, Canada to mas...

Prediction of manufacturing resource requirements from customer demands in mass-customisation production

Mass-customisation production is a new manufacturing approach to produce customised products based on requirements of individual customers while maintaining the quality and efficiency of mass production. Due to the large variations of customised products, the traditional methods for planning manufacturing resources based on volumes of mass produced products are not effective for mass-customization production. In this research, a new manufacturing resource planning method is developed by studying the relations between customer demands and manufacturing resource requirements based on the true data from a mass-customisation production company—Gienow Windows and Doors. In this research, first the relations between the customer demands, modeled by sales data at levels of whole company, sales branches, and markets in sales branches, and the manufacturing resource requirements, modeled by labour requirements of different production lines are studied. Fuzzy pattern clustering method is employed for classifying the resource requirements into patterns to further understand the relations. Based on this study, linear regression and neural network are used to model the linear and non-linear relations between customer demands and manufacturing resource requirements, and to predict the manufacturing resource requirements from available customer demands. A manufacturing resource planning system was developed to demonstrate the effectiveness of this introduced approach.

Manufacturing perspective of enterprise application integration: the state of the art review

Manufacturing enterprise today has become a matter of effective and efficient application of information technology and knowledge-based engineering. Several new manufacturing paradigms such as virtual enterprise (or extended enterprise) and mass customization have resulted in a highly distributed and autonomous manufacturing system. On the one hand, this will increase the competitiveness of a firm in terms of quickly meeting dynamic changes in the market; on the other hand, this will also increase the difficulty of integrating different information and knowledge systems residing in each member firm. This integration is also called enterprise application integration (EAI) (here the term application means information systems or software systems for supporting manufacturing or service activities). The methodology for EAI has been studied for at least a decade; but no satisfactory solution has been found from a practical viewpoint. EAI is becoming even more difficult due to the boom in various enterprise information and knowledge systems (and also to ever increasing competition in the technical software market). The study presented in this paper conducted a critical analysis of existing solutions to EAI. We consider EAI as having two generic issues: semantic integration and syntactic integration. The main problem of semantic integration reduces to the general problem of enterprise or business modelling. The main problem of syntactic integration reduces to the general problem of software architecture of enterprise applications which enables interoperability between any two EAs. While the first issue is studied in the manufacturing field, the second issue is studied in the computing engineering field. In this paper, both issues are put together under the context of EAI and studied. The result of the study, together with our experience with one Canadian manufacturing firm, has led to the identification of several issues to be addressed in the future. We also outline possible ways to approach these issues.

A reconfigurable platform in support of one-of-a-kind product development

In recent years, a variety of Internet-based systems has been developed for the purpose of Rapid One-of-a-Kind or customized Product Development (ROKPD). They can be applied in different stages of the product development process such as to rapidly capture customer requirements, and help produce high-quality products at low cost and short lead-time. Many of the systems, however, do not support rapid adaptation or dynamic reconfiguration of systems and tools for supporting ROKPD in a distributed manufacturing environment. To the authors’ knowledge, the infrastructure of such a reconfigurable platform for supporting distributed manufacturing has never been directly studied. This paper proposes an Internet-based reconfigurable ROKP platform that has been prototyped to serve as a substrate for integrating innovative tools and systems for One-of-a-Kind Production (OKP) companies in New Zealand. The main emphasis of this paper is to investigate how to build the Internet-based reconfigurable ROKPD platform and to design appropriate intelligent tools and systems for the purpose of rapidly and economically producing OKP products in the global environment. A number of recent developments are discussed, including the four open-domain infrastructure of the ROKPD platform, Internet-based data management systems, an integrated product data environment and a cost/lead time control tool.

Optimal concurrent product design and process planning based on the requirements of individual customers in one-of-a-kind production

One-of-a-kind production is a new manufacturing paradigm for producing customised products based on the requirements of individual customers while maintaining the quality and efficiency of mass production. This research addresses the issues in optimal concurrent product design and process planning based on the requirements of individual customers. In this work, a hybrid AND-OR graph is developed to model the variations of design configurations/parameters and manufacturing processes/parameters in a generic product family. Since different design configurations and parameters can be created from the same customer requirements, and each design can be further achieved through alternative manufacturing processes and parameters, co-evolutionary genetic programming and numerical optimisation are employed to identify the optimal product design configuration/parameters and manufacturing process/parameters. A case study is introduced to identify the optimal design configuration/parameters and manufacturing process/parameters of custom window products of an industrial company to demonstrate the effectiveness of the developed method.

Modeling of Evolutionary Design Database

This research introduces an evolutionary design database model to describe design requirements and design results developed at different design stages from conceptual design to detailed design. In this model, the evolutionary design database is represented by a sequence of worlds corresponding to the design descriptions at different design stages. The design requirements and design results in each world are modeled using a database representation scheme that integrates both geometric descriptions and nongeometric descriptions. In each world, only the differences with its ancestor world are recorded. When the design descriptions in one world are changed, these changes are then propagated to its descendant worlds automatically. Consistency of the design descriptions in descendant worlds is also checked when design descriptions in an ancestor world are changed. A case study is conducted to show the effectiveness of this evolutionary design database model.

Adaptive Scheduling and Control of One-of-a-Kind Production

As a typical manufacturing paradigm, one-of-a-kind production (OKP) challenges production scheduling and control differently than mass production. High throughput in OKP is a typical example of mass customization, which is one of the important strategies in the current economy where the objective is to maximize the customer satisfaction by producing highly customized products with near mass production efficiency. As mentioned frequently in this book, OKP is intensely customer focused such that every product is based on specific customer requirements, and products differ on matters of colors, shapes, dimensions, functionalities, materials, processing times, etc. Consequently, a product that is produced on an OKP flow line is rarely repeated.

One-of-a-Kind Production

Despite the numerous competitive advantages of one-of-a-kind production (OKP), the low efficiency and high costs associated with OKP companies threaten to push their business opportunities into the hands of cheaper overseas suppliers.One-of-a-Kind Production introduces a novel strategy and technology to help OKP companies to efficiently mass-produce customized products. In One-of-a-Kind Production, case studies from OKP companies are used to validate the feasibility and effectiveness of the OKP strategy and technology. These case studies include:a structural steel construction company,a manufacturer of specifically ordered compressors and refrigeration systems,a customized high pressure vessel manufacturing company, anda custom window and door manufacturer.To help readers understand OKP strategy and technology, the authors offer a years free access to the OKP Management and Control Software System. This system is based on a new integrated production control and management concept, namely product production structure. It is a useful tool and One-of-a-Kind Production is a valuable guide for production engineers and managerial staff in manufacturing companies, as well as for university researchers and graduate students.

Integration of SPC and performance maintenance for supply chain system

In this paper, a supply chain system is viewed as a maintainable system, and the economic-statistical design of a likelihood ratio control chart with a maintenance application is considered for this system. The supply chain system is described by a three-state: normal state, warning state and failure state. A likelihood ratio control chart is used to monitor the system given that only categorical observations can be obtained. When the chart signals, a full inspection is performed to determine the actual system state (normal or warning), and preventive maintenance is immediately performed in the warning state. In addition, the supply chain system must be corrected upon failure (i.e. corrective maintenance), and should be maintained in a scheduled time (i.e. planned maintenance). A mathematical model is developed for the joint optimisation of the control chart parameters and planned maintenance time based on renewal theory. An example is presented to illustrate how to determine the optimal design parameters. We also investigate the effect of coefficients and statistical constraints on the decision variables and the expected cost.

Capability index of a complex-product machining process

A complex product often requires a high machining precision. This is often achieved by a close-loop machining process to be carried out in several stages, and the measurements, fixture adjustments, and feedback or feed-forward control are inserted after each of these stages. The Complex Product Machining Process (CPMP) Capability Index (CPMPCI) is affected by the control and adjustments in a CPMP, and hence the calculation results of CPMPCI can be used as references to select a proper CPMP. In this paper, we present a novel calculation method of CPMPCI as quality control and improvement technology in a CPMP. A linear model is proposed for describing the variation propagation effect throughout all stages in a CPMP, and an observation model with the pre-specified control and adjustment strategy is employed to calculate the process mean and variation during a CPMP. Finally, through application of Taguchis quality loss function, the CPMPCI calculation method is derived. The feasibility and effectiveness of this method are validated by a case study on a three-stage CPMP.