Peter Butala

A multi-agent approach to process planning and fabrication in distributed manufacturing

In the paper a multi-agent approach to the development of a distributed manufacturing architecture is presented. An essential building block introduced here is the virtual work system (VWS) which represents a manufacturing work system in the information space. The VWS is structured as an autonomous agent and is a constituent entity of an agent network. In the network dynamic clusters of cooperating agents are solving manufacturing tasks. A machining work system and its VWS is demonstrated in a case study. Its role in the agent communication network is discussed in a process planning and fabrication domain.

A Conceptual Framework for Collaborative Design and Operations of Manufacturing Work Systems

The paper addresses a conceptual framework for collaborative product design and related manufacturing system development, operations and maintenance. The framework consists of (1) a conceptual model for collaboration among autonomous manufacturing work systems and (2) an ICT platform which supports collaborative operations over the web. The framework improves visibility, understanding and control of the processes involved and on a practical level provides a platform on which geographically distributed operations can be conducted effectively. The system is developed as an integrated prototype web application. The case study presents the implementation of the concept in the development, operations and maintenance of manufacturing cells for die-casting of aluminum and magnesium components for automotive industry.

Autonomous work systems in manufacturing networks

Manufacturing networks open new possibilities and potentials in design, development and production of complex high-tech products while they combine good characteristics of large companies with advantages of SMEs. In order to manage the structural complexity of a manufacturing network, the paper proposes the business-to-manufacturing network B2MN approach based on the market mechanism. Next, the network nodes in terms of the autonomous work system (AWS) are conceptualized. AWS encapsulates functionalities and competencies related to its management and manufacturing operations, as well as its autonomous information system, which supports autonomous decision-making and cooperation in the network. The case study illustrates the implementation of the AWS concept in industry.

Dynamic structuring of distributed manufacturing systems

Abstract The paper addresses the problem of dynamic structuring of manufacturing systems. The approach presented in this paper is based on the decomposition of manufacturing objectives and the allocation of tasks to autonomous building blocks, i.e. work systems, in a dynamic environment. The allocation is based on a market mechanism that enables the self-structuring and optimization of a manufacturing system by evaluation and selection among competing work systems. The mechanism presented is based on logic relations and constraints. It enables the building of task-oriented manufacturing structures of work systems acting in series and/or in parallel. The approach is discussed in an example in the part fabrication domain.

Assessing operational complexity of manufacturing systems based on statistical complexity

The aim of this paper is to contribute to complex systems thinking in manufacturing organisations through the development of a metric for operational complexity. Operational complexity is concerned with the temporal aspects of coordination and control in manufacturing systems. Statistical complexity from computational mechanics theory is proposed as the metric. The metric can potentially be used to support decision making by objective assessment of complexity. The properties of the metric are explored through simulation studies. The simulation results confirm that the proposed metric captures the intuitive notion of complexity. It is shown that operational complexity is influenced by internal factors such as system structure, as well as external ones such as demand, and that complexity can be managed through the application of appropriate control methods. A case study is presented that applies the metric to real production data. The case study shows that the global recession had resulted in a decreased operational complexity of outputs.

A Conceptual Framework for the Collaborative Modeling of Networked Manufacturing Systems

A manufacturing system is a product, and has to be designed as any other product. Therefore, a need for adequate methodological support and tools for modeling, structuring, and control of the next generation manufacturing systems is recognized. In this study, the adaptive distributed modeling framework for collaborative design and operations of network manufacturing systems is presented. In manufacturing networks, several autonomous partners participate in dynamic design of a manufacturing system, its implementation, and adaptation. In this context collaborative modeling, structuring, and control in distributed manufacturing environment play a vital role. The proposed modeling framework introduces the common modeling space and enables a collaborative definition of modeling building blocks, model design, simulation, and operations support of distributed manufacturing systems in a dynamic environment — which is the realistic nature of the global manufacturing. The prototype of the framework is elaborated in a case study.

The use of 3D laser imaging and a new breast replica cast as a method to optimize autologous breast reconstruction after mastectomy

Aesthetically pleasing and symmetrical breasts are the goal of reconstructive breast surgery. Sometimes, however, multiple procedures are needed to improve a reconstructed breasts symmetry and appearance. In order to avoid additional corrective procedures, we have developed a new method that uses a reverse engineering technique to produce what we call a new breast replica cast (NBRC). The NBRC is a mould of the contralateral healthy breast, designed according to preoperative laser 3D images. During surgery, the mould is used to help shape the new breast. With this method, we are able to achieve breast symmetry in terms of volume, projection, contour, and position on the chest wall more accurately, more quickly, and more safely than before.

Component-based software as a framework for concurrent design of programs and platforms — an industrial kitchen appliance embedded system

Designs of hardware, mechanics and software for a new mechatronic system are to be performed concurrently in order to have a new product in the market in the shortest possible time. Traditionally, major hardware blocks need to be designed and built first. They represent a platform for software writing and testing. A software design concept that enables a parallel design of hardware, mechanics and software is presented. The concept implies creation of a framework for a component-based software design first. Then, a component-based design is performed. At software design time, software components yield embedded system functionality, and they also model hardware and mechanics functionality. As hardware and mechanical parts are built, they are integrated with functionality components, already designed, written and verified. The critical software design task is splitting the embedded software functionality and hardware model into self-contained, self-sufficient components, easy to manage simple interfaces. The concept is demonstrated by a case of designing software for a potato fryer. Software components are designed to be transportable to other industrial kitchen appliances (bain-marie, tilting pan, range) via parameter adjustments only. In the case study of a potato fryer, 90% of microcontroller code was implemented and verified as software components in a C++ Builder environment running on a personal computer at the same time as hardware and fryer mechanical parts were built. 10% of code was written and final parameter adjustments were performed on a simple microcontroller development system.

Self-organization in a distributed manufacturing system based on constraint logic programming

Abstract The paper addresses the problem of self-organization of manufacturing systems. The objective is to overcome the rigidity of conventional hierarchical structures and to introduce structures that are able to adapt to a dynamic environment. The presented approach is based on the concept of Complex Adaptive Manufacturing Systems. It is characterized by a decomposition of manufacturing objectives and allocation of tasks to work systems as autonomous building blocks in a dynamic environment. The allocation is based on a market mechanism that enables self-organization and optimization of a manufacturing system by evaluation and selection among competing work systems. The approach is implemented in the Constraint Logic Programming environment Eclipse and validated in a simulation experiment.

An attempt to implement expert system techniques in CAPP

Abstract This paper presents the development of a generative computer-aided process planning system that covers part of macro level planning activities. The systems task is to generate all appropriate machining operation sequences and select the most promising ones, according to a given set of criteria, while the final choice is to be made by the user. The system acts as a classical “production” system that interprets expert rules on input workpiece data according to the knowledge and data in the engineering knowledge base. By using the technological knowledge in rule form the system largely constrains the solution space and produces a reasonably small set of meaningful alternatives. The advantage of the expert system approach also lies in the programs flexibility which enables easy adjustment of the system according to specific shop-floor environments.