Jerrell Stracener

Incorporating a Measure of Uncertainty into Systems of Systems Development Performance Measures

Technical Performance Measures TPMs historically are used to help the Program Manager in predicting if a program is on a path to achieve required performance. When extended over a developmental timeline, TPMs have provided a deterministic approach for predicting expected operational performance. However, TPMs are difficult to derive for a complex acknowledged system of systems SoS. An SoS Performance Measure SPM has been developed that is equivalent in purpose to TPMs and demonstrated for a deterministic state similar to TPM usage. However, reality indicates that many of the SoS component variables have significant uncertainty associated with them during the SoS development. Therefore, to more accurately account for the ability of an SoS to achieve its desired performance, this variability needs to be accounted for. This paper extends the deterministic SPM concept to a stochastic SPM to account for this uncertainty. An Antisubmarine Warfare ASW mission example is used, and demonstrates how this extension improves the effectiveness of the SPM methodology.

Systems requirements engineering—State of the methodology

There are many references about the characteristics of a good requirement. But what is the process for developing clear, unambiguous requirements, and how do we know when we have defined the requirements successfully? This paper investigates the current state of the methodology for developing complex system requirements. Significant work has been accomplished over the last several years to describe requirements development and systems engineering. This paper identifies and investigates requirements development methodologies and techniques. ©2012 Wiley Periodicals, Inc. Syst Eng 16

A Systems Engineering Approach to Improving the Accuracy of Mobile Station Location Estimation

Enhanced 911 is a first line of assistance for practically every emergency situation, and many cell phone users today expect the same results from an emergency call no matter where they are-whether on the side of the road, in the woods, or in a building. It is a vital part of our nations emergency response and disaster preparedness system. In the context of 911 service, demand for providing reliable and accurate mobile station (MS) location estimation has become a high priority and has gained momentum in recent years. A major challenge in mobile station location estimation is locating an emergency caller within desired accuracy in an adverse environment where non-line-of-site (NLOS) propagation exists. This paper develops a methodology to improve the accuracy of mobile station location estimation in an NLOS environment. A unique feature of this methodology development, compared to other approaches in the literature, is the application of the systems engineering process. While there are many definitions, systems engineering as applied here is an approach and process for developing the preferred solution to a set of requirements. The methodology consists of two stages. In the first stage, a series of time-of-arrival range measurements are made from each base station (BS) to the MS. Binary hypothesis testing on the standard deviation of the range measurements at a given BS is used to determine if the measures are taken under NLOS conditions. Then, if possible, any BS deemed to be NLOS is eliminated from the estimation in the second stage, in which the selected time measurements of several BSs are combined through least squares to estimate the location of the mobile station. Based on a simulation study, the methodology appears to have the potential to significantly improve the accuracy of location estimates in certain situations.

A framework for performance prediction during development of systems of systems

This paper addresses the need for predicting performance in a system of systems (SoS) during development. Historically, technical performance measures (TPMs) along with modelling and simulation have been used by senior decision makers to predict if a system under development will meet the required performance needs. This methodology does not appear to be directly translatable to SoS’s for several reasons including the inherent complexity of the SoS and the operational flexibility the end user has in employing the SoS. An approach to dealing with the SoS performance prediction need is presented that addresses the use and integration of multiple technologies into a SoS and the decision maker’s options in the use of these technologies. This approach is used to develop a metric defined as a ‘SoS performance measure (SPM)’, an equivalent to a TPM for a SoS. An anti-submarine warfare mission construct is used to demonstrate this new metric.

Enhancing the Usability of Human Machine Interface on the Handheld Interagency Identification Detection Equipment (HIIDE)

An essential element of a biometric system is the human machine interface (HMI), both from the user (administrator) and subject perspectives. The HMI has a significant impact on the performance of the system, as it is a key factor in the quality of the biometric sample collected. This paper will consider the implications of the HMI from the user perspective, analyzing the results of user experiences and training with the Handheld Interagency Identity Detection Equipment (HIIDE) Series 4, a device used by the Department of Defense in Iraq and Afghanistan. Results of this task analysis will be in the form of recommendations and considerations for the development of future collection systems. The paper will conclude by presenting the Systems Engineering (SE) based process used in this analysis as well as recommendations for including select SE practices in future biometric system design and development.

First steps in the development of a Program Organizational Architectural Framework POAF

The target audiences for this paper are systems engineers and architects involved in the design of complex systems such as program organizations. This is the first in a series exploring how the design of program organizations developed for the purpose of designing and developing aerospace and defense systems can be optimized. The objective of this paper is to lay the groundwork for an architecture framework for the development of a program organization. The draft standard ISO/IEC 42010 is used to define the structural requirements of the architecture framework. In addition, we use the Zachman Architecture FrameworkTM to organize the framework and the Department of Defense Architecture Framework Version 2.0 DoDAF 2.0 to create the model environment for the Program Organizational Architecture Framework POAF. This approach to defining the POAF ensured that we would have the data needed to support our objective to optimize the design of the program organization and hopefully reduce the number of defects inherent in the design. We also believe that we have sufficiently defined the characteristics of a POAF to spur more research in this area.

A Systems Engineering Approach for Identifying the Most Critical Links of a Highway System: A Framework Consisting of a Methodology and Mathematical Model

A systems engineering approach is used to propose and develop a methodology and mathematical model for identifying the most critical links of a highway system. There are two main benefits for using the methodology and mathematical model. The first is that it provides analysts a platform for developing efficient models pertinent to highway link criticality. The second is that it helps city officials and decision makers with the analysis and planning process involving the highway systems most critical links. The analysis and planning process includes everything from emergency contingency plans to risk analysis and mitigation.

Autonomous Systems Modeling During Early Architecture Development

Abstract Autonomous systems are a complex integration of human intelligence and machine automation capable of adapting to unforeseen events. Proliferation of these systems has accelerated, in part, to meet the ever-increasing demand to develop and use unmanned vehicles to conduct surveillance and reconnaissance missions. During system development, an understanding of the complex relationship between system autonomy, human interaction and machine automation is critical to support early trade studies that address architectural comparisons, scenario concepts of operations, life cycle logistic needs, and total life cycle costs. This paper develops a two dimensional algorithmic methodology and framework tools for contributing to trade space assessments during the early design phases with the intent of supporting design optimization.

Improving tactical biometric systems through the application of systems engineering

To date, the impact of tactical biometric systems has been limited by designs driven by subsystem performance metrics and little consideration for the operational environment in which they are deployed. The design of these systems may be significantly improved by the application of systems engineering practices that consider these and other factors. This study discusses limitations of the current system design approach and proposes a methodology to improve designs. These improvements in design have the potential to dramatically increase the effectiveness and acceptance of biometric technologies in operational environments.

Performance assessments of iris recognition in tactical biometric devices

Tactical biometric devices are used to establish the identity of individuals of interest in various military and law-enforcement scenarios. Most testing of these devices has been conducted in laboratory settings rather than in operationally-realistic tactical scenarios. This study describes an experiment which can viably replace this paradigm by measuring the performance of handheld biometric devices in a variety of tactical environments. The experimental procedure assessed the collectability, quality and matchability of images collected in operationally-realistic scenarios. Iris recognition accuracy was measured using several commercial algorithms. Results illustrate performance degradation in operational results relative to laboratory results; the collection limitations of the devices in operationally-realistic settings; and the effects of operators, subjects, devices and environments on performance. The authors believe that this experiment is unique in its exploration of these elements and that the powerful results presented suggest a need for refinement of design and procurement criteria.