Designing and maintaining systems in a dynamic contemporary environment requires a rethinking of how systems provide value to stakeholders over time. Developing either changeable or classically robust systems are approaches to promoting value sustainment. But, ambiguity in definitions across system domains has resulted in an inability to specify, design, and verify to ilities that promote value sustainment. In order to develop domain-neutral constructs for improved system design, the definitions of flexibility, adaptability, scalability, modifiability, and robustness are shown to relate to the core concept of "changeability," described by three aspects: change agents, change effects, and change mechanisms. In terms of system form or function parameter changes, flexibility and adaptability reflect the location of the change agent-system boundary external or internal respectively. Scalability, modifiability, and robustness relate to change effects, which are quantified differences in system parameters before and after a change has occurred. The extent of changeability is determined using a tradespace network formulation, counting the number of possible and decision maker acceptable change mechanisms available to a system, quantified as the filtered outdegree. Designing changeable systems allows for the possibility of maintaining value delivery over a system lifecycle, in spite of changes in contexts, thereby achieving value robustness.

The scope and complexity of engineered systems are ever-increasing as burgeoning global markets, unprecedented technological capabilities, rising consumer expectations, and ever-changing social requirements present difficult design challenges that often extend beyond the traditional engineering paradigm. These challenges require engineers and technical managers to treat the technological systems as a part of a larger whole. Existing system modeling frameworks are limited in scope for representing the information about engineering systems. This paper presents a conceptual framework and an improved modeling framework for engineering systems. Its value is that it allows engineers and managers an improved means to visually arrange information and structure discourse in a way that facilitates better systems engineering. It augments the existing literature by providing a clear and concise framework for an engineering system, and provides a methodology for engineers to tag and organize systems information in ways that allow for better collection, storage, processing, and analysis of systems engineering data.

Abstract.A traditional approach to system design is to optimize the system with regard to a set of system objectives, as defined in a given context. This approach falls short when designing systems that are capable of delivering sustained value to stakeholders in the face of a rapidly changing world. In order to achieve this value robustness, systems should be designed using natural value-centric time scales, as defined by their contexts, for conceptualizing system timelines. Epoch-Era Analysis is an approach that provides for visualization and a structured way to think about the temporal system value environment. This paper discusses Epoch-Era Analysis as central to a tradespace exploration process for system design comparison and selection, invoking passive or active value robustness design strategies. The analysis can also serve as a socio-technical bridge, integrating the tradespace exploration activities of architects and engineers, which may be traditionally independent efforts in contemporary engineering programs.

Often shifts in context, such as changes in budgets, administrations, and warfighter needs, occur more frequently than high-cost space-based system development timelines. In order to ensure the successful development and operation of such systems, designers must balance between anticipating future needs and meeting current constraints and expectations. This paper describes the application of Multi-Epoch Analysis on a previously introduced satellite radar system program case study, quantitatively analyzing the impact of changing contexts and preferences on "best" system designs for the program. Each epoch characterizes a fixed set of context parameters, such as available technology, infrastructure, environment, and mission priorities. For each epoch, several thousand design alternatives are parametrically assessed in terms of their ability to meet imaging, tracking, and programmatic expectations using Multi-Attribute Tradespace Exploration. While insights on tradeoffs are discovered within a particular epoch, further dynamic insights become apparent when comparing tradespaces across multiple epochs. The Multi-Epoch Analysis reveals three key insights: 1) the ability to quantitatively investigate the impact of "requirements" across many systems and contexts, 2) the ability to quantitatively identify value "robust" systems, including both passively robust and changeable systems, and 3) the ability to quantitatively identify key system tradeoffs and compromises across stakeholders and missions.

Abstract-Uncertainty management is crucial for achieving high performance in enterprises that develop or operate complex engineering systems. This study focuses on flexibility as a means of managing uncertainties and builds upon real options analysis (ROA) that provides a foundation for quantifying the value of flexibility. ROA has found widespread applications ranging from strategic investments to product design. However, these applications are often isolated to specific domains. Furthermore, ROA is focused on valuation, rather than the identification of real options. In this paper, we introduce a framework for holistic consideration of real options in an enterprise context. First, to enable a holistic approach, we use a generalized enterprise architecture framework that considers eight views: strategy, policy, organization, process, product, service, knowledge, and information technology (IT). This expands upon the classical IT-centric view of enterprise architecture. Second, we characterize a real option as a mechanism and type. This characterization disambiguates among mechanisms that enable flexibility and types of flexibility to manage uncertainties. Third, we propose mapping of mechanisms and types to the enterprise architecture views. We leverage this mapping in an integrated real options framework and demonstrate its benefit over the traditional localized approach to ROA.