Engineering Change Research Articles

Concept of a Multi-Agent System for Optimised and Automated Engineering Change Implementation

AbstractEngineering changes are necessary to stay competitive, unavoidable and occur more frequently with increased product complexity. Currently, scheduling of engineering changes into production and supply chain is a manual process. With new possibilities in the field of artificial intelligence, this publication presents the vision of a flexible multi-agent system with four agents and a single shared database. By autonomously scheduling changes and predicting KPI impacts of implementation dates, the agent-system provides additional capacity and decision-making support to the organisation.

Characteristics and driving forces of vegetation dynamics in Inner Mongolia Autonomous Region from 1992 to 2018

Human activities related with construction and destruction are one of the important drivers for vegetation dynamics. Using remote sensing to explore the quantitative monitoring process and driving force of vegetation succession can well reveal the impacts of human activities on ecological background. Based on the vegetation formation group and vegetation formation scales, this study used the European Space Agency's annual land cover data and geo-information TUPU analysis to investigate vegetation succession direction, succession speed, and succession sequence in the Inner Mongolia from 1992 to 2018. The vegetation succession characteristics and its driving forces were then clarified. Results showed that vegetation structure changed dramatically with increasing vegetation and decreasing barren during the study period. The specific annual growth rate was cultivated land (353.10 km2) > grassland (243.92 km2) > forest (-16.22 km2) > shrubland (-120.37 km2) > desert (-556.31 km2). There was a trade-off between the area changes of adjacent grasslands, deserts, and shrublands. Vegetation succession presented a spatial pattern of vegetation expansion and desert reduction, with the succession hotspots concentrated in the West Liaohe River Plain, the desert-grassland junction of central Inner Mongolia, and along the Yellow River. The structure of vegetation succession sequence was complex with progressive succession and regressive succession intermixed. The retention rate of succession flow differed among different communities. Most of the succession flow was intercepted by the grassland and shrubland community of vegetation formation group and the grassland and cropland rainfed community of vegetation formation. The core driving forces of vegetation dynamic succession are agriculture and animal husbandry production, economic development level, population size, ecological engineering, and climate change. As a case study of plantsociology and landscape ecology, our results could provide scientific guidance for optimizing vegetation patterns and enhancing the spatial division and succession level of ecological measures.

A modeling framework to support the implementation of engineering changes in designing complex products

A modeling framework to support the implementation of engineering changes in designing complex products

Metabolic Engineering Strategies for Improved Lipid Production and Cellular Physiological Responses in Yeast Saccharomyces cerevisiae

Microbial lipids have been a hot topic in the field of metabolic engineering and synthetic biology due to their increased market and important applications in biofuels, oleochemicals, cosmetics, etc. This review first compares the popular hosts for lipid production and explains the four modules for lipid synthesis in yeast, including the fatty acid biosynthesis module, lipid accumulation module, lipid sequestration module, and fatty acid modification module. This is followed by a summary of metabolic engineering strategies that could be used for enhancing each module for lipid production. In addition, the efforts being invested in improving the production of value-added fatty acids in engineered yeast, such as cyclopropane fatty acid, ricinoleic acid, gamma linoleic acid, EPA, and DHA, are included. A discussion is further made on the potential relationships between lipid pathway engineering and consequential changes in cellular physiological properties, such as cell membrane integrity, intracellular reactive oxygen species level, and mitochondrial membrane potential. Finally, with the rapid development of synthetic biology tools, such as CRISPR genome editing tools and machine learning models, this review proposes some future trends that could be employed to engineer yeast with enhanced intracellular lipid production while not compromising much of its cellular health.

The coastal aquifer recovery subject to storm surge: Effects of connected heterogeneity, physical barrier and surge frequency

Storm surge, a worldwide phenomenon triggering the vertical saltwater infiltration, is likely to exacerbate coastal groundwater salinization due to geologic heterogeneity, anthropogenic engineering and climate change. This study analyzed the combined effects of connected heterogeneity, physical barrier and surge frequency on the coastal aquifer recovery. A series of modeling cases were investigated using HydroGeoSphere in the heterogeneous and equivalent homogeneous aquifer. The heterogeneity setting is composed of different connectivity level of hydraulic conductivity field. The simulation results of single storm surge event demonstrate that the connected heterogeneity elevates the salinized extent and reduces the aquifer recovery time due to a number of preferential flow paths. In comparison to the equivalent homogeneous aquifer, heterogeneity alleviates the maximum salinized extent and vertical intrusion distance due to the accelerated mixing of salinized groundwater with fresh groundwater. Physical barrier, classified as subsurface dam and cutoff wall, leading to different groundwater discharge pattern is tailored to investigate the influences of the permanent subsurface engineering on the aquifer recovery. Our results show that the connectivity level controls the salinization pattern subject to physical barrier. Then, the repetitive storm surge events were simulated to investigate the effects of surge frequency. For the low-frequency surge event, the variation of salinized metric is the repetition of the unimodal curve in the single surge event. Nevertheless, for the high-frequency surge event, the residual salt mass cannot be flushed out over the simulation period, especially for the low-connectivity aquifer. Meanwhile, the high-frequency surge event broadens the differences of aquifer recovery process due to physical barrier. These findings have critical implications for coastal groundwater management which is facing the substantial environmental risks of surge-induced vertical saltwater intrusion derived from geologic heterogeneity and climate changes.

Engineering Change Risk Assessment: Quantitative and qualitative change characterization

Currently, computer-aided design (CAD) systems are very important for the design of any engineering products. CAD systems have undergone enormous progress. They are becoming more and more intelligent and automated. However, those systems still need improvement and still have flaws that need to be corrected in order to improve and develop the productivity and efficiency of the design process. Mechanical products are often complex and composed of multiple components so, consequently, an Engineering Change (EC) that affects a module or a single component will certainly influence the rest of the assembly. This phenomenon is called Change Propagation (CP). Therefore, in order to propagate a change that affects an assembly component easily, it is important to predict the Change Propagation Path and the impact of this modification on the rest of the assembly components. Hence, CP becomes an easy task. This paper focuses on the risk assessment of an engineering change, in order to enhance the predictive capacity of engineering change management methods. In fact, a full analysis must be made to measure the real impact of such modifications as well as their feasibility. To this end, the authors proposed a matrix-based approach, which results in a Risk Matrix. This is the product of the Relationships Matrix and the Influences Matrix which are constructed based on the data extracted at an early stage. In fact, the CAD assembly model contains a lot of important information that is extracted using Application Programming Interface (API).

ZnIn2S4 and ZnIn2S4 based advanced hybrid materials: Structure, morphology and applications in environment and energy

A schematic representation of the ZnIn2S4 nanocomposite with enhanced activity for energy and environmental applications. • ZIS-based photocatalysts are used for energy and environmental remediation. • ZIS can be utilized for development of ternary metal chalcogenides. • ZIS-based photocatalysts efficiency can be enhanced by various modifications. • This review highlights the recent progress of ZIS based photocatalyst. • Various environmental pollutants are removed using ZIS-based photocatalysts. In past years, solar energy is only the ideal source of energy. But due to the development of technology, the photocatalytic method is one of the clean methods used for environmental remediation and energy shortage problems. Semiconductor photocatalysts are used to overcome the problem of global energy scarcity. ZnIn 2 S 4 (Zinc Indium Sulfide) has recently gained wide attention due to its unique morphological properties such as low cost, chemical stability, and adjustable band gap. Various modifications like metal, non-metal doping, vacancy engineering, and other surface changes are used to enhance the capability of ZnIn 2 S 4 (ZIS). This review discusses the photocatalytic effect of ZIS and its various applications like removal of pollutants, reduction of carbon dioxide, H 2 production, nitrogen fixation, Li-ion batteries, and optoelectronics. In the end, a brief outlook has also provided for future directions and various challenges in ZIS-based materials.

A modular adaptive residual generator for a diagnostic system that detects sensor faults on engine test beds

Abstract. It is a great challenge to apply a diagnostic system for sensor fault detection to engine test beds. The main problem is that such test beds involve frequent configuration changes or a change in the entire test engine. Therefore, the diagnostic system must be highly adaptable to different types of test engines. This paper presents a diagnostic method consisting of the following steps: residual generation, fault detection and fault isolation. As adaptability can be achieved with residual generation, the focus is on this step. The modular toolbox-based approach combines physics-based and data-driven modeling concepts and, thus, enables highly flexible application to various types of engine test beds. Adaptability and fault detection quality are validated using measurement data from a single-cylinder research engine and a multicylinder diesel engine.

МОДЕЛЬ ПРОЦЕССОВ УПРАВЛЕНИЯ ИНЖЕНЕРНЫМИ ИЗМЕНЕНИЯМИ В ИЗДЕЛИЯХ НА ПРОМЫШЛЕННОМ ПРЕДПРИЯТИИ

The issues of the influence of engineering changes in the industrial enterprise products on the goods competitiveness and the enterprise itself are considered, internal and external causes of changes are identified, and the need to formalize the engineering change management system is substantiated. A control model is proposed, which is based on three control loops: engineering changes, product competitiveness and manufacturability, and interaction with the external environment. When concretizing the goals, objectives and parameters of engineering changes at an enterprise a generalized model can help to identify a system of adequate measures designed to create conditions for the enterprise short-term and long-term development while maintaining the competitiveness of manufactured products and the economic stability of the growth as a whole.

Research on the Main Influence of Engineering Change on Construction Project Cost

Research on the Main Influence of Engineering Change on Construction Project Cost

Simulation study on transient performance of a marine engine matched with high-pressure SCR system

The high-pressure SCR system is suitable for low-speed marine engines that burn high-sulfur fuel, but it will cause the increase of the exhaust back pressure of main engine, which will affect the main engine’s performance and fuel consumption. At the same time, due to the large weight and size of the SCR reactor, the overall heat storage performance of the SCR reactor is large, which makes the temperature difference between the front and back of the turbine in the start-up and shutdown of the main engine and transient conditions, affecting the transient response performance of the turbine. In this paper, 6S46ME marine low-speed diesel engine and its high-pressure SCR system are taken as the research object, the co-simulation model is constructed by using GT-Suite coupled with a programming software, and the accuracy of the test model is verified. The influence of high-pressure SCR system on the performance of main engine is analyzed, and it finds that the fuel consumption of the main engine at low load increases significantly greater than that at high load, and the exhaust temperature of the main engine changes differently at different loads. On this basis, the co-simulation model was used to analyze the matching performance of high-pressure SCR system under the transient conditions such as the main engine Tier II/Tier III mode switching process, fast-loading, normal-loading and fast-unloading. The results show that the slow cut-in/cut-out of SCR reactor is beneficial to the stable operation of the main engine system, and the cut-in/cut-out time of high-pressure SCR system greatly affects the transient fuel consumption of the main engine, and the maximum increase of fuel consumption is about 3.6 g/kW·h; In addition, the thermal inertia of the reactor has a greater impact on the performance of the main engine at low load, but not at high load.

An interpretable machine learning approach for engineering change management decision support in automotive industry

As an essential part of the Product Life Cycle (PLC), the time-to-market of products is influenced by Engineering Change Management (ECM) processes. An Engineering Change (EC) is part of a formal process in industry to describe, rationalize, determine, release components for final production or make changes to already released design. It includes information about shape, functionality, production location, cost, and other relevant data entries. The duration from creation to the approval of a change request can take weeks or even months, without apparent reasons for the bottleneck. In addition, changes to one component can lead to unexpected chain reactions to other components. Therefore, identifying impacts of changes is challenging for all Original Equipment Manufacturers (OEMs). To address the above challenges, the authors have developed and built a machine learning-based decision support solution in this article. Community detection and stacking algorithms were applied to build more robust models. Impacts and lead time of Engineering Change Requests (ECRs) are predicted and explained by Local Interpretable Model-agnostic Explanations (LIME). A case study was conducted on real-world data from an automotive company. After evaluation with industry experts, the solution approach was proved to have positive contributions to increasing the quality, efficiency, and transparency of the existing ECM processes.

Requirement-driven engineering change management in product design

Product design change is often triggered by external factors. As product is composed of various components and complex relations among them, predicting change propagation of the upstream component and subsequent influence on product design change is a great challenge. In current researches, most of the methods for engineering change (EC) prediction are focused on a single index, e.g., cycle or workload. Besides, logical relations between product components are rarely considered in the product design change. In this paper, an evaluation model of change propagation incorporating multiple indices and logical relations is proposed to manage the ECs. The primary result of this work is the provision of a development support to efficiently acquire the optimal design change solution when a changed requirement is proposed. Requirement is regarded as the source of design change. Requirement-component relation is established, and component-component relation is constructed in terms of interface types between components. Logical relations (i.e., AND, OR, XOR) between downstream components are proposed and the interface types are applied to judge the logical relation. Requirement-component relation, logical relation between components are applied to generate the change propagation paths. Then ant colony optimization (ACO) is used to optimize the generated change propagation paths and the optimal design change solution is demonstrated to the designers automatically. Finally, a prototype software system is developed and a case study is detailed.

Evaluation and projection of the annual maximum streamflow in response to anthropogenic and climatic effects under nonstationary conditions in the Hanjiang River Basin, China

Abstract The flood regimes have been changing due to the climate change and human activities. Evaluating the flood risk under nonstationarity is critical to water resource management authorities in disaster reduction. In this study, the annual maximum streamflow (AMS) was used to analyze the nonstationarity in flood frequency in the Hanjiang River (HJR) Basin. A Generalized Additive Model for Location, Scale and Shape (GAMLSS) is employed to characterize nonstationarity in the AMS with time, as well as climatic and anthropogenic factors. Additionally, changes of the AMS in response to future climate change and human activity are also investigated. Results indicate that flood behavior can be better described by the nonstationary model with physically based covariates than that with time and the stationary model, implying that flood regimes of the HJR Basin are mainly influenced by anthropogenic and climatic factors including reservoir, precipitation and temperature. The precipitation and temperature projected by the Statistical Downscaling Model (SDSM) under two climate scenarios (RCP2.6 and RCP4.5) in the HJR Basin are characterized by an increasing trend over the period of 2006–2100. Furthermore, an increasing trend was found in the AMS during 2051–2100, indicating that flood risk is likely to increase in the future in the HJR Basin due to the climate change alone without further changes in hydrological engineering and flood management. The results quantified the flood frequency under nonstationarity conditions with physically based covariates and provided information to the decision-makers to address the potential risks posed to the HJR Basin.

A New Generation of Hardware-in-the-loop Simulation Technology Combined with High-performance Computers and Digital Twins

Liquid rocket engines are complex equipment with long maintenance cycles and high fault diagnosis costs. Therefore, hardware-in-the-loop simulation combining software and hardware has become the best choice. A hardware-in-the-loop simulation platform framework is proposed based on a V-type development model and related digital twin technology, and the main content of the framework is introduced. Based on the development process of the platform, a certain type of liquid rocket engine is taken as the object to verify the results. The results show that the platform can well simulate the engine changes under different faults, and has versatility and high real-time performance.

A highly robust thrust estimation method with dissimilar redundancy framework for gas turbine engine

An accurate thrust estimation method is of great importance for implementing direct thrust control scheme on gas turbine engine in that the in-flight thrust cannot be measured. Meanwhile, some interference factors, such as sensor noise, engine-to-engine variations, engine performance deterioration and changes in atmospheric condition, may have adverse effects on the accuracy of thrust estimation. However, these factors are not fully considered in the design of the existing methods. To ensure the accuracy in practical application, a highly robust thrust estimation (HRTE) method is proposed in this paper. This method is a fusion of three dissimilar hybrid estimation modules, each consisting of a physics-based module and an error-compensated module. Compared with the existing pure data-driven methods, its innovations are as follows: 1) a hybrid framework for thrust estimation is proposed, which helps get rid of the dilemma of learning high-dimensional thrust data and improves the accuracy and robustness. 2) a dissimilar redundancy framework is designed for thrust estimation, which helps improve the adaptivity to those interference factors, especially the tolerance to sensor noise. A series of simulation tests eventually show that the HRTE method has high accuracy and robustness in practical application.

Improving engineering change management by introducing a standardised description for engineering changes for the automotive wiring harness

Engineering change management is a key part in the development of products that requires a lot of resources and time. A key problem is the lack of a shared ontology to describe engineering changes. This creates problems, additional effort and hinders the digitalisation of the engineering change management. This is especially true for the development of the automotive wiring harness where a low degree of automation together with the occurrence of many changes in a multi-variant system poses a big challenge. A description that is unambiguous, comprehensive and coherent is needed. The research presented in this paper tackles this problem. A standardised description for the engineering change management for the automotive wiring harness is introduced in this publication. The authors outline the approach that has been used to create a systematic description. The validation of the standardised description is based on two approaches: a case study of a development project and an ongoing development project. The validation shows that 94% of all engineering changes can be described in the proposed standardised way. Concepts where the standardised descriptions can be used to improve the engineering change process are outlined at the end of the paper. The paper thereby presents a way that directly improves the engineering change process and the product development process. It enables the further improvement of the engineering change management by providing a basis for an automatic processing, evaluation and implementation of engineering changes.

Influence of Company Policy towards Conditions for Engineering Change: An Industrial Case Study

The implementation of innovation in an industrial company closely linked to engineering change. Often, innovation becomes as a factor of initiating the engineering change. For successful implementation of innovations, it is requiring to create an efficient system of engineering change and the corresponding policy. The aim of this article was to conduct a case study of an industrial company and to identify the factors that influence the process of innovation and engineering change, paying particular attention to the factor of company policy towards engineering change. The article analyses the literature sources related to the topic, examines the data of the social survey of employees of the selected industrial company, identifies the problematic areas, and provides insights for the improvement of these areas.

Engineering changes - research findings and future directions

Today's global competitive market and diverse advancements of technologies force any firms to focus on core business processes to launch their product on time to market. Though there is more literature on engineering changes (ECs), the sufficient frame of reference is not sufficiently developed in terms of its classification. Hence, a brief sorting to help researchers and academicians in understanding ECs from broader outlook is necessary. In this research work, the literature on ECs categorised on the basis of: 1) problematic environment; 2) approach and methodology adopted to improve organisation performance. Total 231 published articles were classified and examined for future research opportunities by using the literature gaps. A timeline representing related papers is also provided to understand ECs relation with respect to product development and operations. To strengthen the research findings and future directions, a case study included related to ECs influence on automotive supply chain.

Engineering changes - research findings and future directions

Today's global competitive market and diverse advancements of technologies force any firms to focus on core business processes to launch their product on time to market. Though there is more literature on engineering changes (ECs), the sufficient frame of reference is not sufficiently developed in terms of its classification. Hence, a brief sorting to help researchers and academicians in understanding ECs from broader outlook is necessary. In this research work, the literature on ECs categorised on the basis of: 1) problematic environment; 2) approach and methodology adopted to improve organisation performance. Total 231 published articles were classified and examined for future research opportunities by using the literature gaps. A timeline representing related papers is also provided to understand ECs relation with respect to product development and operations. To strengthen the research findings and future directions, a case study included related to ECs influence on automotive supply chain.