Understanding life cycle social impacts in manufacturing: A processed-based approach

Developing sustainable products and processes is growing in importance due to increasing regulation, consumer interest, access to information, and competitive forces. In order to adequately evaluate the sustainability of products and processes, there is a need to consider the impacts from all three pillars of sustainability – society, environment, and economics. There are substantial challenges to identifying and understanding the social impacts associated with manufacturing activities. This paper provides a framework for characterizing the social impacts of manufacturing throughout the life cycle of a product or process. Social impacts occur on various scales in manufacturing, from the level of a unit process to the level of the enterprise. Additionally, manufacturing activities impact consumers, communities, and larger political/spatial realms. This paper identifies key characteristics of social impacts associated with manufacturing that should be considered to more effectively address the social dimension of sustainability for products and processes. Examples involving a typical manufacturing process – welding – are presented to illustrate the utility of the framework.     

Data quality assessment: The Hybrid Approach

Various techniques have been proposed to enable organisations to assess the current quality level of their data. Unfortunately, organisations have many different requirements related to data quality (DQ) assessment. For example, some organisations may need to focus on ensuring regulations are met rather than reducing costs. Due to this, organisations may be forced to follow an assessment technique, which may not wholly fit their needs and current situation. Therefore, we propose and evaluate the Hybrid Approach to assessing DQ, which demonstrates how to dynamically configure an assessment technique as needed while leveraging the best practices from existing assessment techniques.     

A novel folded-torus based network architecture for power-aware multicore systems

Multicore computers are expected to be used to process a higher volume of data in the future. Current mesh-like multicore architecture is inadequate to increase memory-level-parallelism because of its poor core-to-core interconnection topology. In some architecture, each node has communication and computation components – switching component of such a node consumes power while the node is only computing and vice versa. In this paper, we propose a folded-torus based topology to improve performance and energy saving. In this architecture, nodes are separated between network switches and computing cores. Using folded-torus concept, we develop a scheme to connect the components (switches and cores) of a multicore architecture. Experimental results show that the proposed architecture outperforms Raw Architecture Workstation (RAW), Triplet Based Architecture (TriBA), and Logic-Based Distributed Routing (LBDR) architecture by reducing the switches more than 53%, the power consumption by up to 71%, and the average delay by up to 58%.     

Estimation of backlog and delay in OFDM/TDMA systems with traffic policing using Network Calculus

Achieving quality of service (QoS) in OFDM based networks depends, among other factors, on mechanisms for traffic policing or control. Aggregate traffic in high speed networks can present multifractal characteristics such as bursts over a wide range of time scales, heavy tailed inter-arrival time densities, self-similarity and long-range dependence. These properties are followed by a degradation of quality of service for the traffic flows. In this paper, we firstly propose a policing algorithm based on multifractal traffic modeling, evaluating its performance in comparison to other algorithms. We present a more precise in general envelope modeling process in order to efficiently police the input traffic to the system. Further, we present an approach based on Network Calculus for estimating quality of service parameters, such as mean queue length (backlog) and delay. We analyze these two parameters for an OFDM/TDMA based simplified WiMAX system with and without the application of traffic modeling based policing algorithms. In other words, we propose an approach for evaluating some QoS parameters of an OFDM/TDMA system where the traffic is policed. We also evaluate the performance of the proposed algorithm in policing the traffic in an OFDM/TDMA system.     

Minimizing test-point allocation to improve diagnosability in business process models

Diagnosability analysis aims to determine whether observations available during the execution of a system are sufficient to precisely locate the source of a problem. Previous work deals with the diagnosability problem in contexts such as circuits and systems, but no with the adaptation of the diagnosability problem to business processes. In order to improve the diagnosability, a set of test points needs to be allocated. Therefore, the aim of this contribution is to determine a test-point allocation to obtain sufficient observable data in the dataflow to allow the discrimination of faults for a later diagnosis process. The allocation of test points depends on the strategies of the companies, for this reason we defined two possibilities: to improve the diagnosability of a business process for a fixed number of test points and the minimization of the number of test points for a given level of diagnosability. Both strategies have been implemented in the Test-Point Allocator tool in order to facilitate the integration of the test points in the business process model life cycle. Experimental results indicate that diagnosability of business processes can be improved by allocating test points in an acceptable time.     

Selection of third party software in Off-The-Shelf-based software development—An interview study with industrial practitioners

The success of software development using third party components highly depends on the ability to select a suitable component for the intended application. The evidence shows that there is limited knowledge about current industrial OTS selection practices. As a result, there is often a gap between theory and practice, and the proposed methods for supporting selection are rarely adopted in the industrial practice. This paper's goal is to investigate the actual industrial practice of component selection in order to provide an initial empirical basis that allows the reconciliation of research and industrial endeavors. The study consisted of semi-structured interviews with 23 employees from 20 different software-intensive companies that mostly develop web information system applications. It provides qualitative information that help to further understand these practices, and emphasize some aspects that have been overlooked by researchers. For instance, although the literature claims that component repositories are important for locating reusable components; these are hardly used in industrial practice. Instead, other resources that have not received considerable attention are used with this aim. Practices and potential market niches for software-intensive companies have been also identified. The results are valuable from both the research and the industrial perspectives as they provide a basis for formulating well-substantiated hypotheses and more effective improvement strategies.     

A framework for developing home automation systems: From requirements to code

This article presents an integrated framework for the development of home automation systems following the model-driven approach. By executing model transformations the environment allows developers to generate executable code for specific platforms. The tools presented in this work help developers to model home automation systems by means of a domain specific language which is later transformed into code for home automation specific platforms. These transformations have been defined by means of graph grammars and template engines extended with traceability capabilities. Our framework also allows the models to be reused for different applications since a catalogue of requirements is provided. This framework enables the development of home automation applications with techniques for improving the quality of both the process and the models obtained. In order to evaluate the benefits of the approach, we conducted a survey among developers that used the framework. The analysis of the outcome of this survey shows which conditions should be fulfilled in order to increase reusability.     

Synthesis a Petri net based control model for a FMS cell

Petri nets have been recognised as a high level formal and graphical specification language for modelling, analysis, and control of concurrent asynchronous distributed systems. This paper presents a PN model, synthesised by an extended version of the knitting synthesis technique. This method, as an incremental design approach, establishes the conditions under which the fundamental behavioural properties of the synthesised systems are fulfilled and preserved. That is, the synthesised models are live, bounded, and reversible (cyclic). A Petri net with the aforementioned properties is called a well-behaved Petri net system which is guaranteed to operate in a deadlock-free, stable, and cyclic fashion. Well-behaved Petri net models, synthesised using the proposed method can be compiled into control codes and implemented as real-time controllers for flexible manufacturing systems. The significance of this paper is due to the application of an extended version of knitting synthesis technique to a real life example of a flexible manufacturing system.     

Reference free part encapsulation: Materials,machines and methods

Reference Free Part Encapsulation (RFPE) is an automatic, universal workholding process developed by researchers at the Massachusetts Institute of Technology and the University of California-Berkeley. The process encapsulates the stock by freezing it in a low melting point material during machining and transfers datums from one setup to another by refilling and restoring the encapsulation to a known shape after each setup. This paper describes the encapsulator materials and machines developed to test and demonstrate RFPE. The encapsulation material must satisfy stringent thermal properties, and a process is described that concludes that the tin–bismuth eutectic is ideal. The similarities of the encapsulation process to manufacturing processes such as die casting and injection molding are considered; however, it is shown that many intrinsic differences exist between the encapsulation process and injection molding or die casting. Two encapsulation machines are presented. The first is a larger encapsulation machine capable of forming encapsulations with a 6 in. by 6 in. footprint. The second, a much smaller portable machine capable of forming encapsulations with a 2 in. by 2 in. footprint, is also presented. Special features of each encapsulation machine are highlighted and various design decisions are discussed.     

A traceability information model for CNC manufacturing

This paper proposes an information model for tracing CNC manufacturing operations. The objective of the model is to assure that traceability data is comprehensive and available for every CNC machined product, independent of the relationship between the subcontractor and the contractor. The prominent feature of the model is a link between CNC report data for a product instance, the CAD design and the CAM data. This link enables users to browse the traceability data and understand the relationships between the manufacturing process, the CAD design and the CAM data. The link is independent of the systems used to build the CAD and CAM data, and allows the users to be sure the manufactured product contains the required characteristics. Then if a product instance fails, this linkage will make possible to analyze the trace data and identify any exceptions or unusual conditions in the manufacturing process.