Computer Integrated Manufacturing Environment Research Articles

I-DEMATEL method for integrated manufacturing technology selection

Purpose – Computer integrated manufacturing (CIM) refers the manufacturing concept based on the use of computers to control and exchange information for the entire production process. As a result, manufacturing can be faster and less error-prone. However, managing and implementing technologies in the CIM environment are challenging processes for managements and manufacturing organizations. These processes become complex and tedious when one is dealing with many decision parameters. The paper aims to discuss these issues. Design/methodology/approach – This study reports an Interval Decision Making Trial and Evaluation Laboratory (i-DEMATEL) method for evaluating and selecting the CIM technologies that takes into account management objectives. This method can relieve the limitation of the relationship matrix about the assumption of the symmetrical relationship. As a result, it can solve complicated relationship structure problems. Findings – Based on a survey on the current technologies in manufacturing institutes, a case study is demonstrated to present the application of the model. The i-DEMATEL approach takes into account all decision parameters for evaluating and implementing CIM technologies and shows CNC/DNC technology is the most suitable for this case study. Originality/value – The proposed method mitigates the shortcomings of non-fuzzy and fuzzy methods in pertaining literature.

Knowledge–based dynamic scheduling and decision support

The purpose of this article is to illustrate the role that knowledge–based system technologies can play in the development and implementation of more effective decision–support systems. The prototyping of a knowledge–based decision–support system (KBDSS) for supporting the complex, resource–constrained problem of scheduling subsystems and experiments for NASA's space station programme is discussed and serves to highlight various concepts. The dynamic payload scheduling (DYPAS) system, unlike most previous scheduling approaches, is capable of handling the many dynamic elements which characterise a broader class of scheduling problems such as those related to flexible manufacturing systems and computer–integrated manufacturing environments. Also, the integration of knowledge–based decision support, and operations research technologies into a more generic knowledge–based, scheduling shell is discussed, as well as, directions for future research for accomplishment of this shell.

Extraction of Process Parameters from a Sheet Metal Part Model

Process planning in a computer integrated manufacturing (CIM) requires integrated system for design and manufacturing activities. For sheet metal part, feature recognition and feature reasoning of a product model for process planning is an essential component of CIM environment. Research work for feature recognition and reasoning has been addressed in literature, which is limited to the geometric and topological information but actual process parameters requited for manufacturing operation is still an open issue. Our research is for extraction of process parameters from a sheet metal part model which is in STEP Format. These process parameters can be used in sheet metal manufacturing to control the operations. This paper presents extraction of process parameters for a sheet metal feature from a sheet metal part model (STEP Format). This work then formulates the feature processes in terms of extracted process parameters, material properties, sheet metal dimension and feature dimension. The actual operation in real manufacturing environment is identified as extension of the proposed work. The extraction of process parameters for sheet metal operation is demonstrated with case studies.

An improved ant colony optimization approach for optimization of process planning.

Computer-aided process planning (CAPP) is an important interface between computer-aided design (CAD) and computer-aided manufacturing (CAM) in computer-integrated manufacturing environments (CIMs). In this paper, process planning problem is described based on a weighted graph, and an ant colony optimization (ACO) approach is improved to deal with it effectively. The weighted graph consists of nodes, directed arcs, and undirected arcs, which denote operations, precedence constraints among operation, and the possible visited path among operations, respectively. Ant colony goes through the necessary nodes on the graph to achieve the optimal solution with the objective of minimizing total production costs (TPCs). A pheromone updating strategy proposed in this paper is incorporated in the standard ACO, which includes Global Update Rule and Local Update Rule. A simple method by controlling the repeated number of the same process plans is designed to avoid the local convergence. A case has been carried out to study the influence of various parameters of ACO on the system performance. Extensive comparative experiments have been carried out to validate the feasibility and efficiency of the proposed approach.

Robust localisation of automated guided vehicles for computer-integrated manufacturing environments

As industry moves toward an era of complete automation and ‘mass customisation’, automated guided vehicles (AGVs) are used as material handling systems. However, the current techniques that provide navigation, control, and manoeuvrability of automated guided vehicles threaten to create bottlenecks and inefficiencies in manufacturing environments that strive towards the optimisation of part production. This paper proposes a decentralised localisation technique for an automated guided vehicle without any non-holonomic constraints. Incorporation of these vehicles into the material handling system of a computer-integrated manufacturing environment would increase the characteristics of robustness, efficiency, flexibility, and advanced manoeuvrability. OPSOMMING

An effective hybrid graph and genetic algorithm approach to process planning optimization for prismatic parts

Computer-aided process planning is an important interface between computer-aided design and computer-aided manufacturing in computer-integrated manufacturing environments. In this paper, the complicated process planning is modeled as a combinatorial optimization problem with constraints, and a hybrid graph and genetic algorithm (GA) approach has been developed. The approach deals with process planning problems in a concurrent manner by simultaneously considering activities such as sequencing operations, selecting manufacturing resources, and determining setup plans to achieve the global optimal objective. Graph theory accompanied with matrix theory, as the basic mathematical tool for operation sequencing, is embedded into the main frame of GA. The precedence constraints between operations are formulated in an operation precedence graph (OPG). The initial population composed of all feasible solutions is generated by an elaborately designed topologic sort algorithm to the OPG. A modified crossover operator guaranteeing only feasible offspring generated is used, two types of mutation strategies are adopted, and a heuristic algorithm is applied to adjust the infeasible plan generated by the mutation operator to the feasible domain. A case study has been carried out to demonstrate the feasibility and efficiency of the proposed approach.

Manufacturing message specification (MMS) based open manufacturing system

Manufacturing equipment should be integrated to construct a computer integrated manufacturing (CIM) environment, but several economical and technological difficulties may surface when heterogeneous systems are integrated into each other. Manufacturing message specification (MMS) can be effective in such case, but the problem is that MMS-related products are comparatively expensive and most existing manufacturing equipment does not support MMS. This study focused on developing a gateway suitable to a non-MMS-compatible CNC machine-tool, and on implementing an open system interconnection (OSI) upper layer on TCP/IP. The development system was applied to a cell controller by means of heterogeneous equipment under the CIM environment and to evaluate its interoperability and portability.

Open manufacturing system using MMS service and object oriented manufacturing equipments

Manufacturing equipments should be integrated to construct CIM (Computer Integrated Manufacturing) environment, but several economical and technological difficulties may be arisen in case heterogeneous systems are integrated into each other. MMS (Manufacturing Message Specification) can be effective in such a case, but the problem is that MMS-related products are comparatively expensive and the existing manufacturing equipments mostly do not support MMS. This study was focused on developing a gateway suitable to a non-MMS-compatible CNC machine-tool, and on implementing OSI (Open System Interconnection) upper layer on TCP/IP. The development system was applied to a cell controller by means of heterogeneous equipments under CIM environment, and to evaluate interoperability and portability.

Modelling a quality assurance information system for product development projects with the UML approach

To support the application of information technology in quality management, the current paper presents a case study of quality assurance information system modelling for product development projects in a small- to medium-sized enterprise. The object-oriented modelling approach of unified modelling language (UML) was employed. The graphical and well-defined symbols are ideal for modelling complex manufacturing operations. The modelling process was detailed through the depiction of examples for individual diagrams. Through the modelling process, the computerization of product development projects management was realized and a prototype for company-wide application of the approach was established. In addition, the model will provide manufacturers with guidance in comprehending the modelling techniques of UML for achieving computer-integrated manufacturing environments.

Flexible fixturing for workpiece positioning and constraining

Flexible fixturing is an important aspect of any flexible manufacturing system (FMS) and computer integrated manufacturing (CIM) environment. The production analysis for fixturing within an FMS environment is presented. Various approaches to flexible fixturing are briefly described. The reconfigurable fixturing is one of the most appropriate flexible fixturing techniques for CIM environment. Reconfigurable and/or automated modular fixturing employs a number of fixture modules that are set up, adjusted and changed to form different fixture layout. The requirements for locating and constraining workpieces are presented. In addition, computer‐aided planning and analysis of fixture set up are discussed.

Incorporated tool selection system using object technology

Tool selection is perhaps one of the most important functions in a process planning system because the selection of a tool affects the selection of machining parameters, jig and fixture selection, production rate, cost of the product, and the resulting accuracy. Therefore computer-aided tool selection (CATS) is an essential element within a computer-aided process planning (CAPP) system (C. Koulamas, Tool requirements in multi-level machining systems, International Journal of Production Research, 29 (2) (1991) 417–437.), and in turn in a Computer Integrated Manufacturing (CIM) environment. This paper proposes an object–oriented methodology for selecting the tooling parameters for parts in a CIM environment. As this system can be incorporated into both static and dynamic process planning systems, it is termed as Incorporated Tool Selection Systems (ITSS). The steps of the methodology are discussed in detail, together with an example.

Rule management for integration of information systems

This paper proposes an integration approach that extends a global operation model with the rules for integration of various information systems in an information-driven CIM (computer integrated manufacturing) environment. A declarative rule language, which follows the ECA (event, condition, and action) paradigm, is introduced. The rule language allows powerful event specifications and has rich rule execution semantics. Hence, active rules satisfying the needs of various applications such as business rules, integrity constraint management, access control, alerting and configuration management in a HAD (heterogeneous, autonomous and distributed) environment will enable integration of applications without semantic loss. A rule management system (RMS) architecture that extends the Object Management Group (OMG) object model, which is selected as the underlying global operation model, with the proposed rule language and a prototype system based on the architecture are also described. With the proposed rule language and RMS, heterogeneous information systems can be integrated along with the application knowledge. Further, passive and isolated information systems can be changed to active and integrated information systems through the reactive behavior of the rules supported by the proposed approach.

A WWW computer integrated manufacturing environment for rapid prototyping and education

This paper describes an overview of a system integration project in which the development of a multimedia educational tool for designing simple mechanical parts has resulted in new procedures for Computer Integrated Manufacturing (CIM). The new procedures utilize the Internet for seamless integration of Computer Aided Design (CAD), Computer Aided Process Planning (CAPP), and Computer Aided Manufacturing (CAM). The result is a WWW-based CIM environment that not only promotes Design for Manufacturability, but seeks to decrease manufacturing time in a rapid prototyping service based on milling (Sarma 1995, Sarma et al., 1996). Furthermore, the environment utilizes multimedia to display process histories which are generated through the feedback of sensor data collected during fabrication. Remote designers can use this knowledge to monitor the manufacturing process and to redesign if necessary. The paper begins with the description of a specific case study called Reuleaux! , which allows students to design interesting parts while at the same time simplifying some of the downstream process planning and fixturing issues that occur in machining.

A PDES/STEP-based information model for computer-aided process planning

Computer Aided Process Planning (CAPP) constitutes one of the most essential elements in Computer Integrated Manufacturing (CIM). Although many CAPP systems have been reported in literature during the last two decades, few of them are compatible enough to integrate easily with other systems in the CIM environment. One major reason is the lack of an effective method to represent the information required by CAPP, and to unify such information with the information of other systems in the CIM environment. Indeed, this problem has received relatively inadequate attention in the recent research of CAPP systems. In this paper, an information model for CAPP is developed by using the object-oriented modeling and the Product Data Exchange Step / STandard of Exchange Product data (PDES/STEP) techniques. The model consists of the part information model, the process plan information model, and the production resource information model. The EXPRESS language or the EXPRESS-G diagram is used to represent these models. Indeed, the proposed information model will greatly improve the CAPP system’s capability of effective integration with other systems in the CIM environment, and, ultimately, to facilitate the implementation of the whole CIM strategy in manufacturing enterprises.

Probe orientation for coordinate measuring machine systems using design models

The rapidly increasing usage of coordinate measuring machines in computer-integrated manufacturing environments underscores the need for a more science-based approach to inspection than the current ad hoc approach now in place. In this context we address one element of the inspection process, namely, the location of sample points. We present a method for evaluating the location of sample points using the workpiece model from the design. Accessibility analysis is used to determine possible interference between the workpiece model and probe model.

Architecture of a multimedia communication system for technical documentation in a modern factory

This paper examines the influence of multimedia communication services and electronic document systems in the management of technical documentation within a modern factory. After a brief introduction in Computer-Integrated Manufacturing (CIM) and multimedia communication systems, the role of technical documentation in a CIM environment is examined, and the architecture of a Distributed Multimedia Electronic Document System (DMEDS) is proposed. The basic features/operations and the constituent parts of the proposed DMEDS are then analysed. Two of them, the network infrastructure and the necessary software structure, are examined in considerable detail. Finally, a number of important design issues are addressed, and some conclusions are drawn.

Derivation of selection criteria of CIM database using IDEF 0

Integration is the heart of a Computer Integrated Manufacturing (CIM) system. Most of the advanced manufacturing systems are data oriented and the integration of functional subsystems is carried out through data sharing among the sub-systems. However, in a dynamic environment, like manufacturing, where a large amount of heterogeneous data are generated continuously, the data management becomes complex. To manage these huge amount of data, an integrated database system for the CIM environment is needed. This paper presents data characteristics derived using ICAM DEFinition (IDEF 0) and Data Flow Diagram (DFD). A detailed analysis for deriving the selection criteria of the CIM database from the proposed data model is also presented.

Strategies for planning and implementation of flexible fixturing systems in a computer integrated manufacturing environment

In general, for any manufacturing operation to be successful, parts must be located and held to remain in position and orientation when subjected to external forces during the manufacturing operations. The traditional approach to fixturing involves designing and manufacturing special-purpose fixtures. These fixtures are generally dedicated devices designed and manufactured for specific parts and manufacturing operations. Flexible fixturing technology involves employing a single fixturing system to hold workpieces of various shapes and sizes. Such systems have reached the embryonic stage of implementation into manufacturing environment. Therefore the integration of current and future flexible fixturing systems into the manufacturing processes becomes an important issue for future work in computer-integrated manufacturing (CIM) environment. The approach to CIM is dependent on the functional model of the company. Therefore, the implementation of any sub-systems within it must be studied on an individual basis. However, in order to plan and implement new technologies, such as flexible fixturing systems, within CIM environment, certain requirements must be met and guidelines must be followed. The strategies for planning and implementation of flexible fixturing systems within the larger frame work of CIM environment are presented. Some guidelines for designing and developing the interconnection of the data bases are also discussed.

Implementing integrity constraints of EXPRESS in an active object-oriented database

A framework for engineering information exchange is proposed for an information-driven computer integrated manufacturing (CIM) system, using the ISO STEP EXPRESS specification language and an active object-oriented database. The framework allows both the engineering data and its integrity constraints specified using EXPRESS to be stored in the active object-oriented database. Using triggers for userdefined integrity constraints, the active object-oriented database enables application programs to share the engineering data without any concern about the integrity constraints. That is, integrity checking is performed by the database management system, not by individual application programs. Further, it can resolve the problem of engineering semantics loss, and integrate various existing computer aided engineering tools in a heterogeneous CIM environment. The translation framework is described along with appropriate translation examples. A prototype design system based on the framework and comparisons with ot...

A Distributed Real-Time Transaction Processing Environment for the CIM Applications

The paper presents a distributed transaction processing environment that permits the management and the coordination of distributed transactions for real-time Computer Integrated Manufacturing (CIM) applications. The environment has a hierarchical architecture which consists of four layers. The first layer, which represents the nucleus of this architecture is a Real-Time Operating System (RTOS). The RTOS provides the services necessary to enable the applications to meet their timing and throughput constraints. The Manufacturing Messaging Specification (MMS), supported by the ISO as an application layer standard, constitutes the second layer to support messaging communications to and from programmable devices in a CIM environment. The MMS standard introduces a complete set of services for different types of programmable devices as well as the communication protocol needed to support the transfer of data and services parameters. The third layer is composed of a Multi-Server Concept (MSC) specification which provides coordination and management levels to execute a service request by a client over an MMS object distributed over different remote servers. A Transaction Processing Facility (TPF) constitutes the fourth layer of the proposed environment. The TPF guarantees the Atomicity, Consistency, Isolation, and Durability (ACID) properties, defined by the ISO, of the distributed transactions by specifying the communications protocol and services needed to meet these properties.