Understanding the Elements of Executable Architectures Through a Multi-Dimensional Analysis Framework

The objective of this dissertation study is to conduct a holistic investigation into the elements of executable architectures. Current research in the field of Executable Architectures has provided valuable solution-specific demonstrations and has also shown the value derived from such an endeavor. However, a common theory underlying their applications has been missing. This dissertation develops and explores a method for holistically developing an Executable Architecture Specification (EAS), i.e., a meta-model containing both semantic and syntactic information, using a conceptual framework for guiding data coding, analysis, and validation. Utilization of this method resulted in the description of the elements of executable architecture in terms of a set of nine information interrogatives: an executable architecture information ontology. Once the detail-rich EAS was constructed with this ontology, it became possible to define the potential elements of executable architecture through an intermediate level meta-model. The intermediate level meta-model was further refined into an interrogative level meta-model using only the nine information interrogatives, at a very high level of abstraction

Adding Executable Context to Executable Architectures: Enabling an Executable Context Simulation Framework (ECSF)

A system that does not stand alone is represented by a complex entity of component combinations that interact with each other to execute a function. In today\u27s interconnected world, systems integrate with other systems - called a system-of-systems infrastructure: a network of interrelated systems that can often exhibit both predictable and unpredictable behavior. The current state-of-the-art evaluation process of these system-of-systems and their community of practitioners in the academic community are limited to static methods focused on defining who is doing what and where. However, to answer the questions of why and how a system operates within complex systems-of-systems interrelationships, a system\u27s architecture and context must be observed over time, its executable architecture, to discern effective predictable and unpredictable behavior. The objective of this research is to determine a method for evaluating a system\u27s executable architecture and assess the contribution and efficiency of the specified system before it is built. This research led to the development of concrete steps that synthesize the observance of the executable architecture, assessment recommendations provided by the North Atlantic Treaty Organization (NATO) Code of Best Practice for Command and Control (C2) Assessment, and the metrics for operational efficiency provided by the Military Missions and Means Framework. Based on the research herein, this synthesis is designed to evaluate and assess system-of-systems architectures in their operational context to provide quantitative results

Application of Executable Architectures in Early Concept Evaluation

This research explores use of executable architectures to guide design decisions in the early stages of system development. Decisions made early in the system development cycle determine a majority of the total lifecycle costs as well as establish a baseline for long term system performance and thus it is vital to program success to choose favorable design alternatives. The development of a representative architecture followed the Architecture Based Evaluation Process as it provides a logical and systematic order of events to produce an architecture sufficient to document and model operational performance. In order to demonstrate the value in the application of executable architectures for trade space decisions, three variants of a fictional unmanned aerial system were developed and simulated. Four measures of effectiveness (MOEs) were selected for evaluation. Two parameters of interest were varied at two levels during simulation to create four test case scenarios against which to evaluate each variant. Analysis of the resulting simulation demonstrated the ability to obtain a statistically significant difference in MOE performance for 10 out of 16 possible test case-MOE combinations. Additionally, for the given scenarios, the research demonstrated the ability to make a conclusive selection of the superior variant for additional development

Application of Executable Architecture in Early Concept Evaluation using the DoD Architecture Framework

The increasing complexity in the development of today\u27s modern warfighting systems demands a systematic evaluation approach in the assessment of the envisaged capability and estimating the cost effectiveness, especially in the early stages of Concept Development. This research focused on the development of early Concept evaluation methodology through the use of Executable Architecture (EA) through the System Architecting process. Particularly, the methodology was applied in the assessment of a proposed Multi-tiered Unmanned Aircraft System System-of-System that is designed provide target acquisition and conduct dynamic strike on Theater Ballistic Missile launchers. Through the implementation of the evaluation methodology using dynamic modeling of the system-under-design, the research was able to provide quantitative assessment of different design parameters on the overall system effectiveness, as measured using a set of pre-determined Measures-of-Effectiveness. Specifically, Innoslate was used to develop the EA model of a fictitious multi-tier Unmanned Aircraft System System-of-Systems, and provided quantitative assessment of the overall system performance due to changes in the design parameters. Specification, the research showed that the proposed evaluation methodology provides system architects with the tool to 1) evaluate different design parameters, 2) understand the overall system capability given sub-system capabilities, and 3) determine sub-system requirement given desired system performance

A TOSCA-Based Conceptual Architecture to Support the Federation of Heterogeneous MSaaS Infrastructures †

Modeling and simulation (M&S) techniques are effectively used in many application domains to support various operational tasks ranging from system analyses to innovative training activities. Any (M&S) effort might strongly benefit from the adoption of service orientation and cloud computing to ease the development and provision of M&S applications. Such an emerging paradigm is commonly referred to as M&S-as-a-Service (MSaaS). The need for orchestrating M&S services provided by different partners in a heterogeneous cloud infrastructure introduces new challenges. In this respect, the adoption of an effective architectural approach might significantly help the design and development of MSaaS infrastructure implementations that cooperate in a federated environment. In this context, this work introduces a MSaaS reference architecture (RA) that aims to investigate innovative approaches to ease the building of inter-cloud MSaaS applications. Moreover, this work presents ArTIC-MS, a conceptual architecture that refines the proposed RA for introducing the TOSCA (topology and orchestration specification for cloud applications) standard. ArTIC-MS’s main objective is to enable effective portability and interoperability among M&S services provided by different partners in heterogeneous federations of cloud-based MSaaS infrastructure. To show the validity of the proposed architectural approach, the results of concrete experimentation are provided

Incorporating multi-criteria optimization and uncertainty analysis in the model-based systems engineering of an autonomous surface craft

This thesis presents an effective methodology and tool set, that explicitly considers technological uncertainty, to enable design, development, and assessment of alternative system concept architectures for an autonomous unmanned surface vessel (USV) in a system of systems (SoS) context. Complex system designs often fail due to poor communication of customer needs and inadequate understanding of the overall problem. This frequently results in the design team missing the mark in transforming requirements into a successful conceptual design. Effective system design requires a defined, flexible, and structured context within which new technological ideas can be judged. Alternative physical architectures are then modeled, simulated, and compared to find the "best" solution for further examination. This thesis uses model-based systems engineering (MBSE) principles to develop a multi-criteria decision making (MCDM) model that allows designers to perform a solution neutral investigation of possible alternative physical architecture concepts. This ensures a consistent quantitative evaluation of warfighting capability, suitability, effectiveness, technology maturation, and risk before and during a program execution. This effort is in support of an extended program to design a system of unmanned systems intended to provide the DoD with a coordinated, multi-domain, multi-mission, autonomous security and warfighting asset.http://archive.org/details/incorporatingmul109454549Outstanding ThesisUS Navy (USN) author.Approved for public release; distribution is unlimited

Methodology for Value-Driven Enterprise Architecture Development Goals: Application to DoDAF Framework

The Department of Defense Architectural Framework (DoDAF) describes 29 distinct views but offers limited guidance on view selection to meet system needs. This research extends the Value-Driven Enterprise Architecture Score (VDEA-Score) from a descriptive, evaluation protocol toward a prescriptive one by evaluating each DoDAF view and its contribution to the overall objective of the completed architecture. This extension of VDEA is referred to as VDEA-Development Goals (VDEA-DG). The program manager or other decision-makers may use this insight to justify the allocation of resources to the development of specific architecture views considered to provide maximum value. This research provides insight into the Joint Capabilities Integration and Development System (JCIDS) process and policy requirements. Existing guidance of a static list of views prior to DoD milestone approval detracts from the creation of vital architecture for system success. This research shows overlap between the most important views for the considered architecture project and the JCIDS requirements and identifies areas for JCIDS policy improvement. This research also identifies areas where DoDAF does not directly support the creation of capabilities. With additional information on the resources required for creating individual views, the tool could be expanded to identify an optimal build sequence given resource constraints

Application of Reliability and Linear Regression to Enterprise Architecture in Support of the US Air Force\u27s Capability Review and Risk Assessment

This research explored the use of modeling and enterprise architecture in the analysis of Air Force Capabilities. The Air Force accomplishes this through the Capability Review and Risk Assessment (CRRA). The CRRA is currently performed by building architectures which contain Process Sequence Models (PSMs). PSMs are scored by Subject Matter Experts to determine the probability of successfully completing the mission they model and ultimately to determine the risk associated to Air Force capabilities. Two findings were identified. The first is that creating additional architectural viewpoints, some of which are currently being proposed for version 2.0 of the DoD Architecture Framework, can benefit CRRA development. The second is PSMs have fundamental limitations associated with the inability to capture dependencies among activities as well as the inability to get beyond binary success criteria to address issues of capability sufficiency. To remedy these limitations a model called Extended Sequence Models (ESMs) was developed. ESMs extend PSMs by using reliability modeling techniques combined with linear regression to show dependencies between components. This model also allows the effects of capability sufficiency to be captured and related to mission success

Regulatory Compliance in Multi-Tier Supplier Networks

Over the years, avionics systems have increased in complexity to the point where 1st tier suppliers to an aircraft OEM find it financially beneficial to outsource designs of subsystems to 2nd tier and at times to 3rd tier suppliers. Combined with challenging schedule and budgetary pressures, the environment in which safety-critical systems are being developed introduces new hurdles for regulatory agencies and industry. This new environment of both complex systems and tiered development has raised concerns in the ability of the designers to ensure safety considerations are fully addressed throughout the tier levels. This has also raised questions about the sufficiency of current regulatory guidance to ensure: proper flow down of safety awareness, avionics application understanding at the lower tiers, OEM and 1st tier oversight practices, and capabilities of lower tier suppliers. Therefore, NASA established a research project to address Regulatory Compliance in a Multi-tier Supplier Network. This research was divided into three major study efforts: 1. Describe Modern Multi-tier Avionics Development 2. Identify Current Issues in Achieving Safety and Regulatory Compliance 3. Short-term/Long-term Recommendations Toward Higher Assurance Confidence This report presents our findings of the risks, weaknesses, and our recommendations. It also includes a collection of industry-identified risks, an assessment of guideline weaknesses related to multi-tier development of complex avionics systems, and a postulation of potential modifications to guidelines to close the identified risks and weaknesses

Extending relational model transformations to better support the verification of increasingly autonomous systems

Over the past decade the capabilities of autonomous systems have been steadily increasing. Unmanned systems are moving from systems that are predominantly remotely operated, to systems that include a basic decision making capability. This is a trend that is expected to continue with autonomous systems making decisions in increasingly complex environments, based on more abstract, higher-level missions and goals. These changes have significant implications for how these systems should be designed and engineered. Indeed, as the goals and tasks these systems are to achieve become more abstract, and the environments they operate in become more complex, are current approaches to verification and validation sufficient? Domain Specific Modelling is a key technology for the verification of autonomous systems. Verifying these systems will ultimately involve understanding a significant number of domains. This includes goals/tasks, environments, systems functions and their associated performance. Relational Model Transformations provide a means to utilise, combine and check models for consistency across these domains. In this thesis an approach that utilises relational model transformation technologies for systems verification, Systems MDD, is presented along with the results of a series of trials conducted with an existing relational model transformation language (QVT-Relations). These trials identified a number of problems with existing model transformation languages, including poorly or loosely defined semantics, differing interpretations of specifications across different tools and the lack of a guarantee that a model transformation would generate a model that was compliant with its associated meta-model. To address these problems, two related solvers were developed to assist with realising the Systems MDD approach. The first solver, MMCS, is concerned with partial model completion, where a partial model is defined as a model that does not fully conform with its associated meta-model. It identifies appropriate modifications to be made to a partial model in order to bring it into full compliance. The second solver, TMPT, is a relational model transformation engine that prioritises target models. It considers multiple interpretations of a relational transformation specification, chooses an interpretation that results in a compliant target model (if one exists) and, optionally, maximises some other attribute associated with the model. A series of experiments were conducted that applied this to common transformation problems in the published literature