A hybrid methodology for enhancing reliability of large systems in conceptual design and its application to the design of a multiphase flow station

This paper presents a hybrid methodology for conceptual design of large systems with the goal of enhancing system reliability. It integrates the features of several design methodologies and maintenance planning concepts with the traditional reliability analysis. The methodology considers the temporal quality characteristic “reliability” as the main objective and determines the optimal system design. Key ideas from several design methodologies, namely axiomatic design, robust design, and the theory of inventive problem solving, have been integrated with the functional prioritization framework provided by reliability-centered maintenance. A case study of the conceptual design of a multiphase pumping station for crude oil production is presented. The methodology provides a new design tool for determining system configurations with enhanced reliability taking into account maintenance resources and variability.     

Multidisciplinary design methodology for mechatronic systems based on interface model

Mechatronic system is considered as the resulting integration of electrical/electronic system, mechanical parts and information processing. Therefore, to enable a systematic design process of mechatronic systems with a high-level integration, the so-called multidisciplinary integrated design is required. However, neither academia nor industry has yet provided an effective solution, which can fully support the whole design process to achieve such multidisciplinary integrated design. In order to organise the design activities from different disciplines and to aid the designers to achieve the multidisciplinary integrated design, the authors propose a design methodology based on a multidisciplinary interface model. In line with the systems engineering practices, an extended V-model is used as the macro-level process in the proposed design methodology. It starts with identification of requirements on the entire system and ends with a user-validated system. The hierarchical design model is adopted as the micro-level process. It supports the specific design phases where individual designers can structure design sub-tasks and proceed and react in unforeseen situations. To ensure the consistency and traceability between the two levels, the multidisciplinary interface model is proposed. This design methodology is demonstrated by studying the design process of a quadrotor.     

A hierarchical approach to warehouse design

The design of large complex systems, such as warehouses, requires multiple experts and analyses as well as methods to organise and integrate their knowledge. While there are many models for optimising individual aspects of warehouses, there is not, today, a comprehensive design methodology that incorporates and supports all of the design decisions and provides a method to effectively integrate the solutions to these subproblems into a complete warehouse system specification. In this research, we propose a hierarchical design decision support methodology based on decomposing the design problem into a set of subproblems and using a formal model of the system to integrate the solutions to these subproblems. The methodology enables a thorough search of the design space and the identification of many candidate designs for consideration by the design decision maker. The hierarchical design methodology is demonstrated with an example of designing a forward pick area.     

A procedure for the application of product modelling

A procedure for the application of product modelling, resulting from a recently concluded PhD project, is presented. The procedure focuses on the various design of products, where the basic product structure is well defined. The procedure is based on four theory elements: reference models for product modelling, work-study analysis, the task concept from systems theory, and the object-oriented paradigm. The procedure has been tested in a Danish company, and it has been shown via a project of moderate size (in this case using 700 engineering hours, including time for experience collection) that it is possible to get started and use product modelling in industrial companies. Furthermore, it has been demonstrated that the application of product models can save considerable engineering resources (1500-3000 hours per year). Another conclusion is that the product modelling activities are an important means for supporting and integrating engineering activities, as the product modelling activities provide engineers from design and methods engineering departments with valuable insight into the knowledge and procedures used for specifying products and as well as into manufacturing methods.     

Validation of a design methodology

The paper describes how a methodology for the design of computer-aided design systems was transferred from an academic into an industrial environment, where it was used in a large-scale project. The benefits derived from the use of the methodology show clearly its practical value.     

Training needs analysis—a human factors analysis tool

Human factors (HF) engineers have contributed to the reduction of human error, by improving user performance through the design of the user interface. However, there still remains a requirement for user training. This is especially true for complex, high risk processes employing new technology. Reduced manning and downskilling are putting increased pressures on users who, in many activities, still remain the last level of safety protection. In responding to this need, HF engineers now employ a range of tools and methods during the design process, which assist in identifying the training media and training design. Training needs analysis (TNA) offers a structured methodology to facilitate the information gathering process and identify any shortfall between current user performance and that demanded by new technology and designs. By the use of these methods and tools the potential for human error can be reduced, for the following reasons: (a) improved user performance (b) better designed and more efficient training systems. Existing TNA methods have been better suited to the study of existing equipment. This paper describes the training requirements process, and proposes a usable methodology for contractors conducting a TNA in the design of new systems/equipment. It is of particular use where information on the operation or maintenance may be limited.     

基于乡村社区资源的设计创新模式

目的探索基于乡村社区资源的设计创新类型,为设计师参与当代乡村重塑提供方法论指导。方法基于笔者参与的国内外乡村社区营造项目案例以及其他相关知名案例,从资源的利用方式、设计目的和方法与乡村社区的关系两个角度,对设计案例进行分析。结论基于乡村社区资源的设计创新,按照资源利用方式可以分为优势资源继承型、劣势资源转化型、外部资源导入型;按照与乡村社区的关系可以分为为社区设计、"与"/"由"社区设计、社区激发的概念设计。面向农村社区的设计创新体现了"设计3.0"时代的创新特点,即注重学科融合与协同创新的"大设计"整体设计观,立足本地社区资源的同时保持开放式创新的设计方法论,发挥设计社会价值,致力于改善弱势社区生活福祉的设计情怀。     

Axiomatic design of hybrid manufacturing systems in erratic demand conditions

In order to respond to part demands on time in an erratic demand environment, a complete road map for the design of hybrid cellular manufacturing systems (HMS) is proposed in this study, based on axiomatic design (AD) principles, such that all functional requirements of a complete HMS design are satisfied by the corresponding design parameters. With this methodology, first, a preliminary HMS is formed including exceptional operations. To facilitate one-piece flow within the cells of the HMS, these exceptions are eliminated by the proposed decision rules, where alternative machines are employed (Satoglu et al. 2010). Then, the sufficiency of current resource capacities is verified, using a simulation technique. In other words, stock accumulations are identified and then value stream through the system without any obstacles is ensured. These are achieved by means of procedures for identifying and eliminating the bottleneck resources. The proposed methodology is completed with the HMS layout design. This complete methodology based on AD principles is a unique aspect of this study. The methodology is applied on the data of an automotive supplier, and the results are discussed. Finally, using simulation models, it is shown that applying the proposed model results in a statistically significant improvement in lead time of the current available system.     

Manufacturing knowledge verification in design support systems

This paper identifies the need for a verification methodology for manufacturing knowledge in design support systems; and proposes a suitable methodology based on the concept of ontological commitment and the PSL ontology (ISO/CD18629). The use of the verification procedures within an overall system development methodology is examined, and an understanding of how various categories of manufacturing knowledge (typical to design support systems) map onto the PSL ontology is developed. This work is also supported by case study material from industrial situations, including the casting and machining of metallic components. The PSL ontology was found to support the verification of most categories of manufacturing knowledge, and was shown to be particularly suited to process planning representations. Additional concepts and verification procedures were however needed to verify relationships between products and manufacturing processes. Suitable representational concepts and verification procedures were therefore developed, and integrated into the proposed knowledge verification methodology.     

Functional characterisation of mechanical joints to facilitate its selection during the design of open architecture products

New trends in product design require the use of modularity as key feature aimed to improve functional performance and the generation of open architecture products. For mechanical systems, one of the challenges during early design stages of these products involves the proper selection of joining methods among their constructive components. A robust joint selection process must consider product requirements, life cycle analysis and eventual procedures for assembly and disassembly. However, the general approach towards a Design-for-Assembly (DFA)/Design-for-Disassembly (DFD) only considers design, manufacturing and in some cases final disposal stage. Additionally, most of the works found in the literature are merely focused on assembly operations, disregarding economic and environmental benefits from optimising disassembly complexity. Herein, a functional characterisation of mechanical joint methods for the assembly and disassembly activities that take place throughout the product life cycle is proposed, focusing on open architecture products. Additionally, a classification of joining methods, a joint complexity metric valuation and a selection process are proposed for the conceptual design stage. The approach integrates both DFA and DFD principles in a formal methodology. The proposed selection roadmap can be implemented to increase product sustainability positively regarding resources optimisation, operational time and costs in reuse, remanufacturing and recycling tasks.     

An approach to function identification in automated conceptual design of mechanism systems

It has been a challenge in computer-aided conceptual design of mechanism systems as how to describe the kinematic requirements and the functions of a mechanism so that computers can easily recognize, and eventually make automatic selections and combinations among many different types of mechanisms (those combinations include mechanisms of single and multi-degree-of-freedom, and connected in series, or paprallel, or overlap, or feedback). In this paper, a methodology is presented to describe the kinematic characteristics of mechanism systems and their associated requirements so that they can easily recognized by computers. A practical approach is to define “a kinematic function” to represent the kinematic characterizations of a mechanism. It reflects the input and output motion of a given system. This kinematic function can regularly and accurately be described using function units and trees (any function tree consists of more than one function units and is regularly expressed). Because of its uniqueness, the process of mechanism synthesis can be easily recognized by a computer. The methodology demonstrated in the paper has universality and has been successfully incorporated into a software, which has been proven to be an useful tool for the conceptual design of mechanism systems.     

Deadlock prevention technique using additional transitions for Petri nets

ABSTRACT

Siphon control has been utilized as a general methodology for systems of simple sequential process with resource (S³PR) deadlock systems. Although siphon control imposes additional control places on S³PR systems, it cannot guarantee that the maximum permissiveness is achieved. To solve the problem of deadlock prevention for S³PR, a new policy to design a deadlock-free supervisor with the maximally permissive system is proposed using additional transitions. Additionally, this approach can solve the problem of deadlock prevention for systems of sequential systems with shared resources (S4PR) system models.     

An effective genetic algorithm for the resource levelling problem with generalised precedence relations

Resource levelling aims to obtain a feasible schedule to minimise the resource usage fluctuations during project execution. It is of crucial importance in project scheduling to ensure the effective use of scarce and expensive renewable resources, and has been successfully applied to production environments, such as make-to-order and engineering-to-order systems. In real-life projects, general temporal relationships are often needed to model complex time-dependencies among activities. We develop a novel genetic algorithm (GA) for the resource levelling problem with generalised precedence relations. Our design and implementation of GA features an efficient schedule generation scheme, built upon a new encoding mechanism that combines the random key representation and the shift vector representation. A two-pass local search-based improvement procedure is devised and integrated into the GA to enhance the algorithmic performance. Our GA is able to obtain near optimal solutions with less than 2% optimality gap for small instances in fractions of a second. It outperforms or is competitive with the state-of-the-art algorithms for large benchmark instances with size up to 1000 activities.     

Sustainable packaging design: a holistic methodology for packaging design

This study describes a holistic methodology for sustainable packaging design. This methodology studies the combined systems of packaging and the packaged products across the whole distribution chain from manufacturer to end consumer and the life cycle from raw material extraction to the waste phase. It contains a number of indicators that are grouped into the following main categories: environmental sustainability, distribution costs, product protection, market acceptance and user friendliness. The methodology integrates a number of different analytical methods. It is intended to be used in packaging design and optimisation, for idea generation, decision support and as documentation of properties of existing packaging systems. The study describes experiences with the methodology from one case study in the Norwegian Food Industry. The experiences show that the methodology is very comprehensive, and gives a good overview of the properties of a packaging solution. It enables quantitative comparisons between different packaging solutions throughout the design process. The methodology reduces the risk of implementing sub‐optimal packaging solutions. An additional benefit of the methodology is gained by working in cross‐functional teams. One potential drawback is that the methodology can be resource and data intensive. The methodology can be used as a tool box in packaging design, i.e. it is not necessary to use all methods and quantify all indicators to gain benefit. However, all indicators and requirements should be evaluated and considered. In all cases, it should be considered to include additional indicators if important sustainability issues have not been addressed. Copyright © 2010 John Wiley & Sons, Ltd.     

Cost estimation of a service family based on modularity

Companies are competing to offer high varieties of customised services on top of customised products to increase revenues and customer satisfaction. By adopting product family design methodologies, new concepts such as service families and service platforms are adopted in the service sectors. Despite that, increasing diversity in service offerings induces complexity and difficulty in service cost estimation. This research presents a service family cost estimation methodology that is based on service modularity and activity based costing (ABC). A service family is identified by selecting a set of similar services. Subsequently, activities of each service are identified with an activity diagram. The service family is then decomposed into functional and physical elements, where service modules are identified. Service activities are then mapped into relevant service modules using k-mean clustering algorithms, and activities of each service module are segregated into common and specific services using un-weighted pair group method with arithmetic mean. Finally, modified two-stage ABC methodology is applied to estimate the costs for a service family. To demonstrate the applicability of the proposed methodology, a case study is carried out to estimate the cost for a family of aircraft engines.     

A feature recognition methodology for extrudable product shapes

A feature recognition methodology is presented, based on wire frame solid modeler, to recognize hollow or solid extrudable component(s) using both single and multiple hole die. The 2D geometric data obtained from AutoCAD DXF file is processed and entities are classified into line, arc, polyline, circle and ellipse. On further processing, various features are recognized as billet, component and pocket. A component, hollow or solid, is recognized on the basis of product and all its pocket features. The feature data can be formatted for die design and development of related CAPP systems. The methodology has been implemented in the C language on PC 486 and HP 9000 and is demonstrated through an example.     

The fundamentals of barriers to reverse engineering and their implementation into mechanical components

Reverse engineering is a common design strategy in industry. It is a term that has come to encompass a large array of engineering and design activities in the literature; however, in its basic form, reverse engineering is simply the process of extracting information about a product from the product itself. Depending on its use, it may or may not be advantageous to utilize a reverse engineering strategy. As with any rational decision, reverse engineering is only favorable when the benefits from its use outweigh the investment. Therefore, a general understanding of the principles that increase the difficulty or investment required to reverse engineer mechanical products would be helpful for everyone affected by reverse engineering activities. In this paper, we articulate and explore these fundamental principles after reviewing examples from the literature and from our own experience. We then use the principles as a basis for the development of a methodology to build barriers to reverse engineering into new products.     

Cradle-to-grave simulation-based design incorporating multiscale microstructure-property modeling: Reinvigorating design with science

We propose a new paradigm for design that incorporates scientifically oriented research directly and feasibly into engineering design practice. The goal is to use this simulation-based tool earlier in design to achieve more optimized components and systems. The method to accomplish this bridge of science and engineering is by using thermodynamically constrained internal state variables that are physically based upon microstructure-property relations. When the microstructure-property relations are included in the internal state variable rate equations, history effects can be captured. Hence, the cradle-to-grave notion arises. The method to help determine the appropriate microstructure-property relations for the internal state variables is through a multiscale modeling methodology which includes experimentation. As such, scientifically oriented research occurs in the multiscale methodology, and the engineering design practice employs the cradle-to-grave internal state variable model. An example of the multiscale methodology is presented in terms of a cast A356 aluminum alloy used in automotive design, and an example of the cradle-to-grave simulation based design is presented in terms of a stamped product used in a crash scenario.     

Bionic design methodology for wear reduction of bulk solids handling equipment

Large-scale handling of particulate solids can cause severe wear on bulk solids handling equipment surfaces. Wear reduces equipment life span and increases maintenance cost. Examples of traditional methods to reduce wear of bulk solids handling equipment include optimizing transport operations and utilizing resistant materials. To our knowledge, the so-called bionic design has not been utilized. Bionic design is the application of biological models, systems, or elements to modern engineering. Bionic design has promoted significant progress on the development of engineering products and systems. In order to use bionic design for wear reduction of bulk solids handling equipment surfaces, this paper introduces bionic design to bulk solids handling on the basis of analogies between biology and bulk solids handling. In addition, a bionic design methodology for the wear reduction of bulk solids handling equipment surfaces is formulated. Based on the bionic design methodology, two bionic models used for abrasive and erosive wear reduction of bulk solids handling equipment surfaces are proposed.