Modeling multiple human operators in the supervisory control of heterogeneous unmanned vehicles

In the near future, large, complex, time-critical missions, such as disaster relief, will likely require multiple unmanned vehicle (UV) operators, each controlling multiple vehicles, to combine their efforts as a team. However, is the effort of the team equal to the sum of the operator's individual efforts? To help answer this question, a discrete event simulation model of a team of human operators, each performing supervisory control of multiple unmanned vehicles, was developed. The model consists of exogenous and internal inputs, operator servers, and a task allocation mechanism that disseminates events to the operators according to the team structure and state of the system. To generate the data necessary for model building and validation, an experimental test-bed was developed where teams of three operators controlled multiple UVs by using a simulated ground control station software interface. The team structure and interarrival time of exogenous events were both varied in a 2×2 full factorial design to gather data on the impact on system performance that occurs as a result of changing both exogenous and internal inputs. From the data that was gathered, the model was able to replicate the empirical results within a 95% confidence interval for all four treatments, however more empirical data is needed to build confidence in the model's predictive ability.United States. Office of Naval ResearchUnited States. Air Force Office of Scientific Researc

Controlling Change Within Complex Systems Through Pliability

As systems become larger, more complex, and operate for longer periods of time, some change within the system often becomes inevitable. Particularly in systems of systems, with diverse stakeholders, evolutionary development and managerial independence, it is not unusual for constituent systems to change in form or the way they operate. Changeability, the ability of a system to change, is often considered to be a desirable attribute that allows systems to be robust and to adapt in response to changes in context. However, involuntary changes, such as those that occur as a result of a disturbance, are more often problematic than favorable. In some ways, the survivability of a system depends on its ability to prevent, mitigate and recover from unintentional changes within the system brought about by disturbances. For certain large systems of systems, where there are complex interactions and a diverse set of stakeholders, even voluntary changes may be frowned upon, since it may be an expensive and time consuming process to approve changes. This paper discusses pliability, a new “-ility” that places constraints on the changes a system is allowed to make. Pliability is the ability of a system to change, without “breaking” or violating an architecture that the system architects intended and validated. Like changeability, pliability increases robustness by allowing systems to voluntarily change in response to changing contexts, and increases survivability by increasing the likelihood that unintentional changes are still within the set of allowable instances. It also distinguishes allowable changes from those that would require validation and approval from decision makers, making it easier to actually implement those changes in large, complex systems

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

Disturbances and disruptions, both internal and external to the system, are a major concern for system architects who are responsible for ensuring that their systems maintain value robustness no matter what occurs. These perturbations can have multiple causes and can affect a system in multiple ways. This paper presents a taxonomy of disturbances and disruptions to assist system architects and researchers in identifying the ways in which systems can fail to deliver value. By doing so, this taxonomy falls into a larger research effort to develop survivability design principles that will help system architects design systems that prevent, mitigate and recover from disturbances

Revisiting the Question: Are Systems of Systems just (traditional) Systems or are they a new class of Systems?

This paper revisits a question asked and debated widely over the past decade: are Systems of Systems (SoS) just traditional systems or are they a new class of systems? Many have argued that SoS are a new class of systems, but little research has been available to provide evidence of this. In this paper we share highlights of recent research to show SoS not only have a different structure than systems and thus need to be engineered differently, but also may possess different attributes for beyond first use properties (the “illities”) such as flexibility and adaptability as compared to systems. By examining historical examples and by using a maritime security SoS as a research test bed, this paper shows that the “ility” called survivability had some design strategies that were directly mapped from systems and also allowed new strategies that only made sense for a SoS (e.g. vigilance). The paper also shows that some design strategies have a different implementation and meaning (e.g. margin) at the level of a system compared to SoS level. We conclude the answer to the question “Are SoS’s just systems?” is both yes and no. They are manifestly systems but possess properties not found in traditional systems. This is shown to true of the meta-property of survivability as applied against a directed SoS

Investigating alternative concepts of operations for a maritime security system of systems

For complex systems of systems, such as those required to perform maritime security, system architects have numerous choices they may select from, both in the components and in the way the system operates. Component choices, such as the length of a wing or the number of ground control stations, are often considered in tradespace studies, but this paper highlights the operational choices that are often overlooked. Using an unmanned vehicle system of systems as an example, the importance of considering operational choices as well as the highly interdependent nature of operational and component choices is demonstrated, further strengthening the case for careful consideration of operational variables early in the concept phase of the design process. Finally, a high-level methodology for generating and evaluating operational choices is introduced

Managing the impact of change through survivability and pliability to achieve viable systems of systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 195-202).As technology improves, traditional systems are being interconnected into larger systems of systems (SoS) that operate in diverse contexts, where numerous perturbations exist that threaten the ability of the SoS to deliver acceptable value to its diverse set of stakeholders. Furthermore, the systems of systems themselves can change form voluntarily or involuntarily in response to contextual variability or stakeholder whims. Various system properties, or "-ilities" have been defined that may help traditional systems provide value to stakeholders in spite of change, but they have not specifically addressed the issue of systems operating within larger systems of systems. This dissertation defines the concept of viability for engineered systems, as a likelihood that systems will satisfy their stakeholder needs over the system's expected lifetime, and identifies and develops strategies that system architects can use to create viable systems. The concept of viability helps system architects design systems that can survive contextual perturbations, whether they are from entities outside the traditional system boundary, or from other constituent systems within a SoS. In addition to external perturbations, this dissertation addresses the need to ensure that endogenous changes made to improve value delivery, do not inadvertently cause unintended interactions that harm the system overall. This is particularly a concern with the proliferation of systems of systems, and the recent drive towards making systems more changeable as a mechanism for value sustainment in dynamic environments. A new "ility", pliability, is introduced that specifies the limits on how a system can change, without "breaking" or violating an architecture that was intended and validated. Like changeability, pliability increases robustness by allowing systems to voluntarily change in response to dynamic contexts, and increases survivability and robustness by increasing the likelihood that unintentional changes are still within the set of allowable instances. It also distinguishes allowable changes from those that would require validation, reducing the effort required to get those changes approved by a diverse set of stakeholders.by Brian Mekdeci.Ph.D