查看更多>>摘要：Complex engineered systems face protracted design cycles and indefinite lifetimes, leading to discrepancies between expected and actual operating conditions. The field of design for changeability has focused on developing strategies to cope with these discrepancies. Literature has implicitly assumed that future changes can be predicted by system designers, but this assumption does not match observed reality. Often, systems must be modified in unexpected ways to maintain value, limiting the usefulness of standard change mechanisms. To understand how unexpected changes are implemented in practice, we studied the C-130, a setting where one platform performed many missions, and close air support in Desert Storm, a setting where many platforms performed one mission. Through this examination, we find that excess and operator change are key mechanisms for changeability that have been largely ignored by literature. Excess can enable additions to systems without having to remove or swap subsystems out. It is also a critical enabler of modular changes during the operational phase. Operator changes are non-form changes driven by system users who change how their systems are used to gain new capabilities rather than relying on changes to the form of the system. This paper also studies the relationship between these mechanisms to shed light on how changeability is achieved in practice, building the foundation for future work to study tradeoffs of implementing valuable excess during design.
查看更多>>摘要：Decomposition is a critical enabler of complex system development, as it enables both task specialization and efficiency through parallel work. The process of decomposing involves partitioning system parameters into tightly coupled modules and managing any cross-module coupling by designing passive interfaces or through active coordination. A rich literature has developed algorithms and tools to support this process. However, we contend that this view has placed too much emphasis on module selection, and not enough on the interaction with interface design. This perspective has significant implications for lifecycle costs and development time. To that end, this study explores how earlier consideration of interface design can create more valuable options to better navigate performance, cost, and schedule tradeoffs. Specifically, through an abstract simulation experiment, we demonstrate that (1) a sequential approach that first selects modules and then designs interfaces to support those modules, yields lower performance than an integrated approach that considers modules and supporting interfaces simultaneously; and (2) this result is even stronger when schedule and cost are considered as part of the evaluation. In other words, an integrated approach provides more options for project managers seeking to navigate the performance-cost-schedule tradeoff known as the golden triangle. These results emphasize the need for a decomposition aid that adopts a holistic view of the optimization problem, accounting for interface creation, intra-organization collaboration, and valuing nonperformance measures of effectiveness.
查看更多>>摘要：With the increasing complexity of space missions due to technological advancements, model-based systems engineering (MBSE) has become a new paradigm for systems engineering (SE), providing a more formal and accurate system engineering process while reducing costs. However, MBSE does not offer a comprehensive approach for effective system function design. This study introduces a conceptual design approach that integrates axiomatic design (AD) and design structure matrix (DSM) into the MBSE paradigm and applies it to functional and logical design. The research focuses on utilizing the design knowledge encapsulated by system models to facilitate the development of new systems. System models have the potential to bridge different design domains in AD, reveal implicit associations, and offer functional and structural analysis capabilities. To validate our approach, we conducted a case study on an Emergency Response Remote Sensing mission system. This case study demonstrates that our proposed methodology lends formality to traditional AD by deriving AD matrices and DSMs from a system model, thereby enhancing the system's structure while curtailing elemental alterations during iterative design processes. The novelty of this research lies in realizing the integration of traditional design theory with the model paradigm of SE, leading to an effective design solution during the functional and logical design stages.
Eaton, Casey E.Campo, Kelly X.Longhurst, AugustMesmer, Bryan...
343-362页
查看更多>>摘要：The decisions that direct system development are based on assessments of a system, referred to as technical measures. Systems engineers select the set of technical measures for each system, informed by previous systems, guidebooks, and systems engineering research. If guidance for selecting technical measures is contradictory or does not ensure that a satisfactory set is selected, then the selected set of technical measures may not facilitate directing a system development as desired. Within large-scale complex engineered systems development, a technical measure set provides clear targets for a system and can be used to coordinate and integrate efforts by many individuals and teams. This systematic literature review of 89 academic and industry developed engineering literature sources examines over 2500 guidance statements for technical measure selection. Most guidance provides examples or abstract qualities that technical measures should exhibit. Such guidance can result in multiple sets of technical measures that each drive toward different designs. The guidance identifies origins for technical measure selection, such as from stakeholders, but lacks detail on how to elicit a set of technical measures from stakeholders. This research's systematic literature review audits the consistency, contradictions, and omissions in current guidance for selecting technical measures. From these findings, we seek to establish evidence-based research needs in technical measure selection.
查看更多>>摘要：In practice, when an unmanned aerial vehicle (UAV) swarm is not executing a mission, its UAVs will be stored as inventory. To ensure that the UAV swarm can be quickly deployed when needed, it is necessary to assess and predict its storage state. Due to the flexible configuration of UAV swarms and the complex factors that affect them during storage, existing storage state indicators and prediction methods cannot meet the requirements of UAV swarm storage. In order to address these issues, a UAV swarm storage availability prediction method based on agent-based simulation (ABS) is proposed. Considering the degradation of health status, maintenance, support, and other factors during the storage period of UAVs, a UAV swarm storage state measurement metric that covers the storage cycle is proposed. Based on this metric, a UAV swarm storage availability model is established. Then, considering the dynamic adaptability and internal complex interactions of UAV swarms, the ABS is used to realize the modeling and prediction of UAV swarm storage availability. Finally, a UAV swarm rescue case is used to illustrate its scientific validity and accuracy. Therefore, this study offers a scientific and efficient method for measuring the availability of UAV swarms, providing valuable insights for rapid response and decision-making during the transition from storage to deployment. It also presents a viable approach for availability modeling and prediction in complex, emergent swarm systems.
查看更多>>摘要：Commercial-Off-the-Shelf (COTS) parts use is a key strategy that the space industry is embracing to meet an ever-increasing demand for space access and services. Integrating COTS parts into spacecraft architectures is beneficial in many aspects such as integrating modern technologies, reducing costs, improving reliability, accelerating payload fielding, and alleviating supply chain constraints. As COTS parts become more prevalent in spacecraft designs, there is a need to update risk management techniques used in the industry. A COTS centric risk management framework (RMF) does not exist nor do space hardware standards and policies provide detailed guidance. To address this systems engineering gap, this research developed a novel RMF that can be employed when trying to determine if candidate COTS parts are suitable for use in space hardware systems. The COTS parts RMF is a roadmap to identify uncertainties, analyze and evaluate the consequences, and how to mitigate COTS parts-based space system hardware risks. Additionally, to demonstrate its utility, the techniques were placed into practice and validated during the development of a COTS-based space-rated battery built with COTS lithium-ion cells. The risk evaluation process, developed based on the proposed COTS part RMF, was successfully used to uncover and mitigate cell and battery material and design issues. This work significantly improved the battery's performance without hampering the project's schedule, cost, and fielding objectives. The results illustrate the characteristics and benefits of using a focused COTS parts RMF to design, build, and qualify COTS-based space system hardware.
查看更多>>摘要：Developing complex systems like satellites and aircraft organizations involve numerous decision-makers across various levels. These stakeholders, internal or external, express preferences traditionally through textual needs statements. Textual needs statements are easy to formulate and use, but offer limited analytical capacity. Alternative approaches based on decision analysis facilitate representing preferences rigorously but prove resource intensive without accuracy guarantees. Recently, researchers have proposed modal preference logic (MPL) to mathematically represent and reason about stakeholder preferences in systems engineering. Past work has demonstrated MPL's promise in identifying preference inconsistencies. This paper builds on that foundation to advance new theory and methods for systematically measuring detected inconsistencies. It introduces the Inconsistency Magnitude (IM), a rigorously developed metric grounded in minimal inconsistent subsets that sensitively quantifies inconsistencies and the spread of inconsistencies. Underpinning this metric, several theorems are presented that prove key properties across syntax variations. The research computationally exemplifies the metric over sample preference bases exhibiting differing complexity levels of inconsistencies.
查看更多>>摘要：Globalization and growing business dynamics lead to weakly harmonized supply chain (SC) systems. While smart technology offers innovation opportunities, supply chains often lack the integration needed to fully leverage resources and collaboration. A comprehensive systems engineering (SE)-driven model for integrated innovation and optimization of smart SC business models is still missing. This study, through case research at SAP SE's Industry 4.0 division and three automotive companies, identifies key digital transformation objectives and interoperability gaps hindering smart opportunities. Systems engineering, supply chain management (SCM), and artificial intelligence (AI) methods were synthesized into a holistic SE-driven model for transforming and optimizing SC business models. This model integrates management concepts like the theory of ambidexterity and dynamic capabilities, with SE methods capability engineering and complex adaptive systems, and semantic web concepts. Key SE contributions include meta-modeling multi-tier SC architectures, ensuring performance and resilience via simulations, and balancing value exploration and exploitation. Moreover, semantic harmonized and profit-optimized SC ecosystems enable collaborative innovation for flexible, efficient manufacturing-a core Industry 4.0 principle. This SE-driven model, validated by experts, provides a concise view of digital SC business models and a driver of generative design.
Gateau, ThibaultCordero, Sophia SalasVingerhoeds, Rob
438-452页
查看更多>>摘要：CubeSat design has been already studied and formalized but knowledge representation remains a challenge. The management of human-learnt knowledge during the process is not an aspect that is often spoken about. This paper discusses the proposal of integrating a hierarchical planning approach with a model-based one to the open-source Nanospace framework, a web-based application for concurrent engineering during the preliminary design phase of CubeSats. Hierarchical planning aids to introduce commonly tacit human expertise, an aspect that the preliminary design of CubeSats can benefit from. The proposed integration could allow a faster design convergence and faster inspection of candidate architectures The Nanospace framework itself may benefit from an approach bringing in model-based efforts and hierarchical planning facilitate knowledge representation and reuse. A use case on the CREME CubeSat project is detailed, emphasizing how to impregnate the design iterations with experts' knowledge.
查看更多>>摘要：Efficient production systems are necessary for the realization of products that fulfill customer needs and delivery requirements. However, the process of designing the production system has received little academic attention, and today's manufacturing system design processes and architecture are still based on traditional engineering methods. This paper covers a case study using the systems engineering method Concept of Operations and Operational Concept for the design of a human-centric production system for a novel product. A comprehensive prescriptive study was designed, combined with attempts to verify the methods used. The case study applies design methods defined in ISO/IEC/IEEE 15288. A total of six workshops, the development of Concepts of Operations, three levels of Operational Concept, and two validation studies are documented. A total of 166 persons participated, and up to 15 persons participated in the validation workshops. The analysis shows that the design methods addressed gaps identified in literature: (1) the lack of systematic and effective systems engineering design methods in production system design, and (2) the lack of inclusion of human aspects in the production system design. The gaps in the effectiveness of the methods remain to be fully evaluated as the project is still running and will not be concluded until 2025. Recommendations for future work include exploring how ConOps/OpsCon method can be more widely spread and adopted by engineering as a significant artifact for systems understanding for the design of more human-centric, resilient production systems.
NETL
NSTL
Wiley