Muharrem Mane

Variable Resource Allocation Using Multidisciplinary Optimization: Initial Investigations for System of Systems

The concept of a “System of Systems” (SoS) describes a large system of multiple systems – each capable of independent operation – that have been brought together to provide capabilities beyond those of each individual constituent system. Formulating and solving an SoS design problem has become increasingly important, particularly in the aerospace and defense industries, as customers have begun to ask contractors for broad capabilities and solutions rather than for specific individual systems. Part of an SoS design problem is determining the appropriate mix of both existing and yet-to-be-designed systems. While determining an appropriate mix of existing systems falls into the category of resource allocation, including features of a yet-to-be-designed system makes the problem more complicated by requiring the allocation of a variable resource. In this paper, a simple problem using an airline wishing to investigate how a new, yet-to-be-designed aircraft will impact the fleet operating costs provides an example of this type of problem. The resulting statement is a Mixed-Integer, Non-Linear Programming (MINLP) problem. Approaches for MINLP are applied to the problem, and these methods do generate solutions but at generally high computational cost. Using a response surface approach to model the airline design portion of the problem finds good solutions at much lower computational cost. A decomposition approach analogous to those of multidisciplinary optimization is also applied to the problem, in which there is an “allocation domain” and an “aircraft design domain”, and this approach also generates solutions, but at a lower computational cost. The MDOmotivated decomposition approach appears to have promise for the allocation of variable resources challenge presented by many SoS design problems.

Taxonomy to Guide Systems-of-Systems Decision-Making in Air Transportation Problems

a system of systems, many engineering methods and tools used to design and analyze large-scale, but monolithic, systems do not appear to work for systems of systems. This paper presents a three-axis taxonomy that can guide design method development and analysis of alternatives for aeronautical systems of systems. Based on this perspective, two experiments in applying the methods are presented for system-of-systems problems that involve aircraft and/or air transportation. Nomenclature AR = aspect ratio T=W = thrust-to-weight ratio W=S = wing loading

Assessing New Aircraft and Technology Impacts on Fleet- Wide Environmental Metrics including Future Scenarios

The environment and the impact of human activities on the environment have been at the center of attention recently, and air transportation is a contributor to environmental emissions. This paper presents a model that measures the impact of technology and policy changes on future emission levels of the air transportation. The resulting tool models the environmental performance of aircraft and the resource allocation of airlines in order to measure the fleet-wise environmental impact of changes in technology as well as to assess the degree to which policy changes on environmental metrics are achievable. The tool tracks environmental impact in three forms CO2, NOX and airport noise while assuming a benevolent monopolistic airline serves passenger demand. The results reflect key relationships between emission levels, passenger demand, ticket price and aircraft technology over a period of several years.

Fleet-Wide Environmental Impacts of Future Aircraft Technologies

The impact of aviation on the environment has been at the center of attention recently, and thus, the need to assess the impact of air transportation emissions on the environment is evermore present. This paper presents the continuation of research efforts on a Fleet-Level Environmental Evaluation Tool (FLEET) that assesses the fleet-wide environmental impact of future aircraft concepts and technologies while also considering economics and operational decisions of airlines. Specific improvements to FLEET from previous presented papers consist of a larger network of operations that includes international passenger travel, an updated aircraft retirement and delivery schedule, and a set of future aircraft that meet the NASA Sub-sonic Fixed Wing Project emissions and noise goals. Example analysis results reflect key relationships between emission levels, passenger demand, ticket price, and aircraft technology over a period of several years.

Impact of Development Rates of Future Aircraft Technologies on Fleet-Wide Environmental Emissions

To mitigate the environmental impact of aviation while still allowing for growth in air transportations, various organizations – such as NASA – have set goals for advancing technologies that reduce the impact of aircraft on the environment. Meeting these goals would improve the environmental performance of an individual aircraft; however, the environmental impact of air transportation is a fleet-level effect that depends on the combined operation of all aircraft with their associated technologies. Economic factors, like fuel price, also impact aviation emissions, because economic factors drive air transportation demand and drive airline fleet composition. This paper analyzes the sensitivity of environmental metrics to the entry-into-service (EIS) dates of various potential new aircraft and to the penetration rate of these new aircraft into the fleet. The studies also incorporate three potential fuel price change scenarios. The results suggest insights in two areas. First, the level of (carbon) emissions is sensitive to EIS dates of new technology aircraft only during a short period after the introduction; later EIS dates lead to airlines upgauging their fleet to maximize profit. Second, high fuel price reduces demand, which reduces emissions, especially on short routes where alternative modes of ground transport likely exist.

System of Systems Inspired Aircraft Sizing Applied to Commercial Aircraft / Airline Problems

The concept of a “System of Systems” (SoS) describes a large system of multiple systems – each capable of independent operation – that have been brought together to provide capabilities beyond those of each individual constituent system. Formulating and solving an SoS design problem has become increasingly important, particularly in the aerospace and defense industries, as customers have begun to ask contractors for broad capabilities and solutions rather than for specific individual systems. Part of an SoS design problem is determining the appropriate mix of both existing and yet-to-be-designed systems. While determining an appropriate mix of existing systems falls into the category of resource allocation, including features of a yet-to-be-designed system makes the problem more complicated by requiring the allocation of a variable resource. In this paper, a simple problem using two airlines wishing to investigate how a new, yet-to-be-designed aircraft will impact the fleet operating costs provides an example of this type of problem. The resulting statement is a Multiobjective, Mixed-Integer, Non-Linear Programming (MINLP) problem. Approaches for MINLP are applied to the problem, and these methods do generate solutions but at generally high computational cost. A decomposition approach analogous to those of multidisciplinary optimization is applied to the problem, in which there is an “allocation domain” and an “aircraft design domain”. The MDO-motivated decomposition approach appears to have promise for the allocation of variable resources challenge presented by many SoS design problems.

Concurrent Aircraft Design and Resource Allocation Under Uncertainty for On-Demand Air Transportation

The concept of a “System of Systems” (SoS) describes a large system of multiple systems – each capable of independent operation – that have been brought together to provide capabilities beyond those of each individual constituent system. Formulating and solving an SoS design problem has become increasingly important, particularly in the aerospace and defense industries, as customers have begun to ask contractors for broad capabilities and solutions rather than for specific individual systems. Part of an SoS design problem is determining the appropriate mix of both existing and yet-to-be-designed systems that are expected to operate in an uncertain environment. In this paper, the problem of a fractional aircraft management company wishing to investigate how a new, yet-to-be-designed aircraft will impact the fleet operating cost provides an example of a Systems of Systems problem. The daily route network of an ondemand air transportation provider changes every day and, as such, uncertainty becomes part of the problem formulation. A decomposition approach analogous to those of multidisciplinary optimization is applied to the problem and Monte Carlo simulation is performed to address the uncertainty aspects of the operations.

Sensor Platform Management Strategies in a Multi-Threat Environment

The objective of a Ballistic Missile Defense System (BMDS) is to defend the United States, friends and allies, and deployed forces from ballistic missile attack. While effectively intercepting the threat missiles is the ultimate measure of a successful system, the ability to accurately track incoming threats is a key prerequisite. In a BMDS, missile-tracking is the activity of coordinating and managing multiple sensor and computing resources to detect and track threat missiles. Development of specialized and highly capable sensor, computing, and network resources creates a multitude of functional allocation possibilities that promise to increase the effectiveness of the missile-tracking task. This paper presents a taxonomy for the description of missile-tracking architectures and an enterprise-level Agent-Based Modeling and Simulation framework for their evaluation. We find that highly centralized architectures outperform decentralized ones. The dimension of centralization, however, plays an important role in the performance of an architecture; centralized situational awareness coupled with decentralized sensor tasking can still provide quality solutions while presenting the possibility for reduced communication requirements.

Concurrent Aircraft Design and Trip Assignment Under Uncertainty: Fractional Operations

The phrase “System of Systems” (SoS) describes a large system of multiple systems – each capable of independent operation – that have been brought together to provide capabilities beyond those of each individual constituent system. Formulating and solving an SoS design problem has become increasingly important in the aerospace and defense industries as customers have begun to ask contractors for broad capabilities and solutions rather than for specific individual systems. Part of an SoS design problem is determining the appropriate mix of both existing and yet-to-be-designed systems. While determining an appropriate mix of existing systems falls into the category of resource allocation, including features of a yet-to-be-designed system complicates the problem by requiring the allocation of a variable resource. This paper focuses on the representation and solution of the concurrent aircraft design and trip assignment problem of a Fractional Management Company as a system-ofsystems problem considering uncertain operations where demand varies from day to day. The work described here introduces an approach to design aircraft that directly and positively affect s not only aircraft design but also costs related to its operations and allocation. This is a departure from past representations that consider the solution to allocation problems and the solution to aircraft design problems separately. Simultaneously considering the aircraft design and trip assignment problem can take advantage of interactions between these two problems that are intangible if they are considered independently but can result in improved performance for the operator when considered simultaneously.

A Markov perspective on system-of-systems complexity

The development and acquisition of complex systems remains a challenge, especially in the aerospace/defense sector, due to complexities in both program management and engineering design. The interdependencies between component systems form networks that, while enabling capabilities that are beyond those of individual systems, also increase system complexity and risk since disruptions in the development of one system may propagate to other directly or indirectly dependent systems. This paper presents an approach to measure the complexity of networks in the context of system development time. Development disruption propagation is modeled as a Markov chain, where the states are defined as the constituent systems and the transition probabilities as the interdependency characteristics of systems. A proof-of-concept application shows the approach can distinguish between alternate networks and indicates its applicability for managing risk in design and development of systems with significant interdependencies.