Reusability Assessment for Manufacturing Systems

Manufacturing firms have begun reconfiguring and reusing production systems to save resources consumed on system changes that were brought about by the high product variety and frequent model change. As a result, assessing manufacturing system reusability has become an important issue. This paper introduces intrinsic and effective reusability of manufacturing systems and proposes quantitative metrics to assess them. Using an automotive assembly system as example, this paper also explores how system configurations and task allocation affect reusability. Insights from such a study will help improve manufacturing system reuse for families as well as generations of products.     

Augmented Reality Aided Assembly Design and Planning

This paper presents a methodology that integrates the assembly Product Design and Planning (PDP) activities with the Workplace Design and Planning (WDP) activities to improve the efficiency and quality of assembly design and planning at the early design stage. This methodology is implemented in an augmented reality (AR) assembly environment, where engineers can design and plan a product assembly and its assembly sequence through manipulating virtual prototypes in a real assembly workplace. In this AR environment, WDP information are fed back to the designers and engineers in real-time to aid them in making better decisions in assembly design and planning.     

Methodological Approach and Reconfiguration Tool for Assembly Systems

Assembly lines design is intended to solve many problems related to assembly operations. The introduction of a new product should often entail the salvage of existing assembly lines. This work proposes a methodology for assembly line reconfiguration, to rationalize and support the redesign process of assembly systems. This research formalizes a representation model and a method for assembly line reconfiguration. The model describes the main characteristics and significant features of the assembly process. The study is concerned with three fundamental models, the first describes assembly line structures. The second illustrates component assembly features and the third produces all the assembly sequences. The assembly line reconfiguration method provides an analysis and estimation tool on the reconfiguration process complexity. The method proposed is also meant to be a tool to identify the operational flexibility limit. The method results point out the way to implement assembly system reconfiguration and gives detailed information about the assembly line. Each assembly line, facing a new product to be assembled, is processed with the reconfiguration method and receives operative results for reconfiguration process and quality indicators.     

Design Reuse Methodology for Product Family Design

This paper presents a design reuse methodology to facilitate product family design. Three major processes are defined, namely, information modelling, information processing, and solution synthesis and evaluation. The information content assessment (ICA) method is proposed for solution evaluation. This method defines logical steps to compute the information content that is used as a uniform, dimensionless metric of product performances. In a case study, product families of the cellular phone were developed using the design reuse methodology. It is demonstrated that the design reuse method proposed in this paper can effectively manage the product family design processes, and the ICA method provides a useful way for performance evaluation.     

Providing product use knowledge for the design of improved product generations

Current design of improved product generations does not exploit use information from previous products systematically. The emerging shift of manufacturing companies from selling products to providing product service systems, the miniaturization of product-embedded sensors, as well as advances in information technology facilitate a product providers access to operation information of current products, which can be used to improve the development and the quality of follower product generations. The paper presents a framework for the acquisition, aggregation and analysis of product use information as well as for the generation and provision of knowledge for the development of improved product generations. The described approach employs knowledge discovery methods like Bayesian Networks and is supported by an IT prototype of a design assistant system. This prototype has been validated in a use case considering the improvement of a rotary spindle for micro machining.     

Modular design for increasing assembly automation

Modular design can address the need for a high number of product variants and further allow a higher degree of automation in the assembly line. A framework is developed for the simultaneous modular product design and the design of automated manufacturing system. Product designs are optimized for automation using Design Structure Matrix and Modular Function Deployment. Alternative production systems are designed and accessed based on the analysis of assembly steps hierarchically. The implementation of the framework on the design of a production system for furniture assembly, able to handle multiple variants with a large number of components, is demonstrated.     

A multi-agent architecture for plug and produce on an industrial assembly platform

Modern manufacturing companies face increased pressures to adapt to shorter product life cycles and the need to reconfigure more frequently their production systems to offer new product variants. This paper proposes a new multi-agent architecture utilising “plug and produce” principles for configuration and reconfiguration of production systems with minimum human intervention. A new decision-making approach for system reconfiguration based on tasks re-allocation is presented using goal driven methods. The application of the proposed architecture is described with a number of architectural views and its deployment is illustrated using a validation scenario implemented on an industrial assembly platform. The proposed methodology provides an innovative application of a multi-agent control environment and architecture with the objective of significantly reducing the time for deployment and ramp-up of small footprint assembly systems.     

Assembly system design and operations for product variety

Assembly is the capstone process for product realization where component parts and subassemblies are integrated together to form the final products. As product variety increases due to the shift from mass production to mass customization, assembly systems must be designed and operated to handle such high variety. In this paper we first review the state of the art research in the areas of assembly system design, planning and operations in the presence of product variety. Methods for assembly representation, sequence generation and assembly line balancing are reviewed and summarized. Operational complexity and the role of human operators in assembly systems are then discussed in the context of product variety. Challenges in disassembly and remanufacturing in the presence of high variety are presented. We then conjecture a future manufacturing paradigm of personalized products and production and discuss the assembly challenge for such a paradigm. Opportunities for assembly system research are summarized at the end of the paper.     

Development of new concepts and software tools for the optimization of manual assembly systems

Due to growing numbers of differing products and variants, assembly systems with optimized manual workstations have become an efficient alternative to highly automated but less flexible production systems. Especially in the final stage of the product assembly, the flexibility of human employees enables them to meet the requirements for assembling various products and changing volumes. In order to create highly efficient production systems based on human work, it is necessary to develop innovative concepts for the design and organization of manual assembly structures. Another major issue is the development of software tools allowing the facility planner to simulate and optimize the complete design of the assembly structure such as the material flow or manual workstations, e.g. with respect to ergonomics, before construction. These requirements have led to a comprehensive research framework for manual assembly systems.     

Assembly and Disassembly Processes in Product Life Cycle Perspectives

Industrial companies change the paradigms of business operations from optimisation of manufacturing processes to optimisation of products life cycles in order to activate the value of products, taking into account the potentials of product services in all phases of each product's life. From design to the end of their life capital intensive products, like manufacturing or assembly systems, are linked to a manufacturer network by global communication systems. This network allows special services even in the phases of usage and recycling. For this new paradigm it is necessary to develop strategies, methods and technologies to manage the business processes and the information and knowledge required in all phases of a product's life and to industrialise the processes of design, assembly, usage, service and remanufacturing by disassembly and recycling. It is the objective of this paper to define the processes for management of life cycle with a focus on assembly, service and disassembly of capital intensive products.     

CAD model based virtual assembly simulation,planning and training

This paper reviews the state-of-the-art methodologies for developing computer-aided design (CAD) model based systems for assembly simulation, planning and training. Methods for CAD model generation from digital data acquisition, motion capture, assembly modeling, human–computer interface, and data exchange between a CAD system and a VR/AR system are described. Also presented is an integrated methodology for designing, planning, evaluating and testing assembly systems. The paper further describes the implementation of these methods and provides application examples of CAD model based simulation for virtual assembly prototyping, planning and training. Finally, the technology gaps and future research and development needs are discussed.     

Product modularity and assembly systems: An automotive case study

Designing modular products offers a number of advantages. However, modularity may be challenging in terms of production and assembly. In this paper, the influence of product design modularity on assembly systems is investigated. A modular design from the automotive industry is presented and compared with a traditional design. The influence of modularity on the assembly system is discussed including attributes such as production rate, investment cost and product's delivery delay.     

Quality-driven Sequence Planning and Line Configuration Selection for Compliant Structure Assemblies

Assembly sequence planning is an integral part of a new product and process development. However, currently there are very few available approaches to evaluate the impact of assembly sequences on product quality. This paper develops a methodology for Quality-driven Sequence Planning (Q/SP) with consideration to product dimensional quality based on the following three steps: (1) Sequence generation for predetermined line configurations using /(-piece mixed-graph representation of assembly; (2) Dimensional quality model of variation propagation for assembly processes with compliant parts; and (3) Evaluation of sequences based on the multivariate process capability index. The methodology is illustrated using an industrial case study.     

Towards the co-evolution of industrial products and its production systems by combining models from development and hardware/software deployment in cyber-physical systems

Industrial production systems and industrially manufactured products are constantly evolving due to technical innovations and customers’ demands. Therefore, ensuring an optimized co-evolution of both becomes an important yet challenging task. Approaches for model-based systems engineering have been widely investigated and have already had significant impact on industrial practice. However, existing model-based approaches mostly are focusing on particular aspects of a production system and do not provide a holistic approach for optimizing automated production systems, their deployment, and their co-evolution with the product. As a first step towards this direction, this contribution proposes the combination of an engineering approach for aPS based on systems modeling language with models and techniques for deployment of software and hardware to cyber-physical system architectures, which have been investigated in the field of computer science, and motivates the possibilities of a combined approach.     

Open-architecture products

This paper defines open-architecture products (OAPs), a new class of products comprising a fixed platform and modules that can be added and swapped. Customers can adapt OAPs to their needs by integrating modules into the platform. Manufacturers will produce these platforms, while new small companies and customers will develop the modules, thus increasing employment and causing the economy to flourish. At the same time OAPs will provide consumers with the product they desire. Challenges include developing new OAP design software for non-professional designers and new assembly systems to facilitate economical assembly of a large number of product variants.     

Early design verification of complex assembly variability using a Hybrid – Model Based and Physical Testing – Methodology

Design verification in the digital domain, using model-based principles, is a key research objective to address the industrial requirement for reduced physical testing and prototyping. For complex assemblies, the verification of design and the associated production methods is currently fragmented, prolonged and sub-optimal, as it uses digital and physical verification stages that are deployed in a sequential manner using multiple systems. This paper describes a novel, hybrid design verification methodology that integrates model-based variability analysis with measurement data of assemblies, in order to reduce simulation uncertainty and allow early design verification from the perspective of satisfying key assembly criteria.     

Determination of extended availability and productivity for assembly systems using existing data base

Reliable information about the operational availability of assembly or production systems is of great importance for the users of complex production facilities, especially when such facilities operate at their capacity limit. Nowadays, in most cases, the availability of assembly systems is monitored and evaluated using collected status data. This paper presents a new approach for permanent productivity determination of assembly systems based on the usage of in-process acquired product data. This approach is especially applicable for manufacturing systems that produce goods for which complete product traceability is required.     

Assembly Reliability Evaluation Method (AREM)

This paper proposes a new design system for assembly quality evaluation called AREM. It is based on the assembly fault occurrence model reflecting both product design and assembly shops. It prevents faults in assembly shops related to the design of the product. The system has three distinctive features: estimation of faults caused by design, extraction of faulty parts or faulty operations, and analysis of fault phenomena. AREM can distinguish the responsibility of the design and the shop quantitatively. This method is being used for various products in practical production lines, and has proven to be effective.     

A parametric study of joint performance in sheet metal assembly

In sheet metal assembly, joints are designed to facilitate welding the parts and to form various shapes and dimensions of sheet metal products. The most commonly used joints are lap joints, butt joints and butt-lap joints. Different joint configurations have different performance characteristics. One of the performance criteria is the level of dimensional variation in the assembly. This paper presents a parametric study of the dimensional variation characteristics of the three basic joints. An offset finite-element-model-based variation simulation methodology is used in the parametric study in order to take into consideration possible part deformation. This parametric study helps determine the circumstances under which part variation or tooling variation will contribute more variation to assembly variation. These results provide improved understanding of sheet metal assembly processes and provide data for robust product/process design.