Matthew E. Fitzgerald

Architecting Systems of Systems with Ilities: an Overview of the SAI Method

The uncertain and fast-changing nature of operational environments is driving a growing interest in systems that display desirable lifecycle properties (i.e., ilities). A survivable, flexible, or evolvable (among other properties) system is able to sustain value delivery over time by responding to exogenous changes in the operational environment. This paper introduces the SoS Architecting with Ilities (SAI) method, which enables systems architects to design for ilities from the conceptual design phase. An overview of the SAI method is presented, to expose the reader to the most important steps and activities of the method, and how they are specifically targeted at enabling SoS design with ilities.

Exploring Stakeholder Value Models via Interactive Visualization

Abstract In the design of complex systems, models can be used to predict a future systems performance as well as approximate stakeholder preferences on performance. This paper examines the problem of model truthfulness and the challenge of trusting models, with a focus on value models and how they are used to predict stakeholder preferences. A framework is proposed for the analysis of these issues (truthfulness and trust), which is used to discuss the relationship between models and decision outcomes. Interactive visualization is proposed as an efficient and effective method for increasing model truthfulness and model trust, and hence making better decisions. An interactive visualization tool is also presented, and an application of the tool to a complex decision case is discussed.

Game-based Learning for Systems Engineering Concepts

Abstract Game-based learning has the potential to improve the education and performance of engineers and decision makers in the systems engineering field. This paper reviews the arguments for the use of educational gaming, with particular attention to the aspects of game-based learning that are well suited to tackling the complex sociotechnical systems engineering problems that currently are trusted only to experts with years of experience. It also describes the development of an educational game, Space Tug Skirmish, designed to be used as a teaching and research tool for systems engineering core concepts.

Controlling for Framing Effects in Multi-stakeholder Tradespace Exploration☆

Abstract Framing effects have been shown to have dramatic impact on human decision making in many domains, in certain circumstances even driving self-detrimental behavior. Multi-stakeholder tradespace exploration (MSTSE), an emerging technique for advanced multiparty decision making for engineering systems, has displayed many benefits with regards to insight-generation and identification of mutually beneficial solutions. However, for complex problems with no solutions that are individually optimal for each stakeholder, stakeholders may still resist “compromising” from their individual preferred solutions. This occasionally drives a failure to reach agreement, despite a design space with a considerable number of feasible designs with value for all parties. This paper hypothesizes that this result may be caused in part by an unintentional framing of the initial stages of MSTSE as an individual problem, establishing an unrealistically high reference point. Theoretically, this locks stakeholders into a mindset that forces them to “compromise” down, rather than more appropriately building up mutual value from the “no agreement” alternative. This paper addresses the current literature of multi-stakeholder system design, the ramifications of framing on MSTSE, considerations for establishing a more appropriate reference point, and example techniques and visual representations for doing so. A preliminary set of experiments is described to confirm the hypothesized framing effect and to validate visual representations for mitigating its impact.

Multi-Epoch Analysis of a Satellite Constellation to Identify Value Robust Deployment across Uncertain Futures

The value of a system depends heavily on the future contexts it will encounter. For complex space systems with multi-year design and deployment phases, it is useful to design a system so that it delivers value to stakeholders over a wide range of future contexts. EpochEra Analysis, a computational scenario planning approach, decomposes the lifecycle of a system into sequential epochs that each have fixed contexts and value expectations. This paper applies Multi-Epoch Analysis (a subset of Epoch-Era Analysis) along with MultiAttribute Tradespace Exploration (MATE) to the design of a satellite constellation, with the aim of maximizing value across a range of end-user subscription and geographic distribution contexts. The system level tradespace is assembled using a bottom-up iterative approach based on expert knowledge, and accounts for performance attributes metrics such as revisit times, data latencies, observation times, and data downlink volumes. Competing designs consisting of alternative orbital, ground station location, and deployment configurations are evaluated in terms of their fuzzy Normalized Pareto Trace (fNPT) across epochs. The resulting staged deployment strategy delivers robust value based on stakeholder preference across a wide range of future contexts.

Considering alternative strategies for value sustainment in systems-of-systems

Systems of Systems (SoSs) operating in an uncertain world must overcome a variety of challenges in order to sustain value delivery over time. This paper describes strategies for value sustainment, using an application of the “wave model” to represent time-varying SoS Engineering (SoSE) activities and opportunities for SoS-change. A Maritime Security (MarSec) SoS case study is described, and simulation-based Era Analysis is used to evaluate SoS alternatives through different operational environments for an assumed 8-year time frame. Eight SoS designs are evaluated and compared across four strategies in terms of accumulated utility, discounted cost, and total down time. The four value sustainment strategies are: (1) self-recovery, the SoS is not changed (i.e., relating to survivability/robustness); (2) changes in the design of the SoS are allowed (i.e., relating to changeability); (3) changes in the architecture of the SoS are allowed (i.e., relating to evolvability) once, or (4) three times in the eight years. The results provide an example of how quantitative approaches can be used to gain insights into tradeoffs in how SoS architects can create value-sustainable SoSs for the long run.