System architecture pliability and trading operations in tradespace exploration

Abstract

The concept of operations is often assumed when assessing different design variables in a tradespace study for a particular system architecture, The way a system operates, however, has a large effect on its performance, and can often be the only variable through which stakeholders can influence a system after the system is implemented. The concept of pliable system architectures is introduced so that operational variables can be explicitly considered and incorporated into tradespace studies. System transitions can be predicted by pliability, and these transitions can provide insight into other system "ilities" such as changeability, adaptability, flexibility and survivability. Two techniques are introduced in order to demonstrate the usefulness of the pliability concept; (1) a step-by-step process by which operational variables can be identified within a system architecture, and (2) a process by which very large tradespaces can be sampled into a manageable set of system instances that provide maximum insight for the level of effort to model them. As these new concepts and methodologies are new and part of ongoing research, they will need to be tested and validated in future work.

Quantification of changeability level for engineering systems

“…While the first is anchored in the physical object alone, the latter also concerns its interaction with the context. This is in line with the literature . To help illustrate the need for these two different reference domains to describe the changeability level for a system, let us consider a simple example: a versatile offshore ship can be operationally changeable, without performing any physical changes in the design, as it can take on different types of contracts due to its level of inherent multifunctionality.…”

“…One can also characterize an airplane design through its ability to function in different modes of operation, which, for example, can be characterized by the market segment (people vs. cargo) and route characteristics (short vs. long haul). For more detailed ways to classify concepts of operations (CONOPs) for system design applications see Mekdeci et al …”

“…Thus, this research differentiates itself from the research focusing on change propagation of existing systems. In addition, building on Mekdeci, Ross, Rhodes, and Hastings, we expand the system boundaries beyond only considering change of physical design variables, to also include changes in the operational space. Research on operational changeability is often connected with real options (RO) (see Trigeorgis for an overview of RO).…”

System design and engineering trade‐off analytics: State of the published practice

“…The VOSviewer tool provides a thesaurus mechanism to manually combine similar terms and eliminate terms that do not have high discriminatory power within the context of our bibliometric analysis. An example of combining similar terms was to combine the "ilities" based on previous work in systems engineering on combining these terms [10][11][12][13] by mapping them to the term "suitability" in the thesaurus.…”

A taxonomy of perturbations: Determining the ways that systems lose value

“…Perturbations can cause the system to operate differently, either to a viable mode of operation specified in its system architecture [12], or to other some mode of operation. For example, turbulence may force an aircraft to fly a different route and altitude than it normally would fly, increasing the flight time and burning more fuel.…”