ASSIP Study of Real-Time Safety-Critical Embedded Software-Intensive System Engineering Practices

Modern weapon systems increasingly depend on real-time, safety-critical, embedded (RTSCE) software to achieve their mission objectives. In addition, these systems are experiencing far longer service lives than anticipated at their inception. Army weapon system developers are concerned that this combination of factors renders today's software acquisition and development practices insufficient to address the challenges of these software-intensive systems. To address the concern, the Army Strategic Software Improvement Program tasked the Carnegie Mellon Software Engineering Institute (SEI) to assess RTSCE software-intensive systems issues and develop recommendations. The findings of phase one of that study are presented in this report: (1) industry is driving the development of tools for model-based engineering to meet the needs of RTSCE system development, and (2) many opportunities exist for the U.S. Department of Defense (DoD) to gain experience and advance the transition of these tools into DoD programs

System Architecture Virtual Integration: An Industrial Case Study

The aerospace industry is experiencing exponential growth in the size and complexity of onboard software. It also seeing a significant increase in errors and rework of that software. All of those factors contribute to greater cost; the current development process is reaching the limit of affordability of building safe aircraft. An international consortium of aerospace companies with government participation has initiated the System Architecture Virtual Integration (SAVI) program, whose goal is to achieve an affordable solution through a paradigm shift of "integrate then build." Key concepts of this paradigm shift are an architecture-centric model repository as single source for analytical system models, accessed through a model bus, used as a single source for analytical models, and multi-level, multi-fidelity analysis of multiple operational quality attributes of the system and embedded software system architecture. The result is discovery of system-level faults earlier in the life cycle-reducing risk, cost, and development time. The first phase of this program demonstrated the feasibility of this new development process through a proof of concept which is the topic of this report

Resource Allocation in Distributed Mixed-Criticality Cyber-Physical Systems

Large-scale distributed cyber-physical systems will have many sensors/actuators (each with local micro-controllers), and a distributed communication/computing backbone with multiple processors. Many cyber-physical applications will be safety critical and in many cases unexpected workload spikes are likely to occur due to unpredictable changes in the physical environment. In the face of such overload scenarios, the desirable property in such systems is that the most critical applications continue to meet their deadlines. In this paper, we capture this mixed-criticality property by developing a formal overload-resilience metric called ductility. The generality of ductility enables it to evaluate any scheduling algorithm from the perspective of mixed-criticality cyber-physical systems. In distributed cyber-physical systems, this ductility is the result of both the task-to-processor packing (a.k.a bin packing) and the uniprocessor scheduling algorithms used. In this paper, we present a ductility-maximization packing algorithm to complement our previous work on mixed-criticality uniprocessor scheduling [6]. Our packing algorithm, known as Compress-on-Overload Packing (COP) is a criticality-aware greedy bin-packing algorithm that maximizes the tolerance of high-criticality tasks to overloads. We compare the ductility of COP against the Worst-Fit Decreasing (WFD) bin-packing heuristic used traditionally for load balancing in distributed systems, and show that the performance of COP dominates WFD in the average case and can reach close to five times better ductility when resources are limited. Finally, we illustrate the practical use of COP in distributed cyber-physical systems using a radar surveillance application, and provide an overview of the entire process from assigning task criticality levels to evaluating its performance

Results of SEI Independent Research and Development Projects FY 2007

The Software Engineering Institute (SEI) annually undertakes several independent research and development (IRAD) projects. These projects serve to (1) support feasibility studies investigating whether further work by the SEI would be of potential benefit and (2) support further exploratory work to determine whether there is sufficient value in eventually funding the feasibility study work as an SEI initiative. Projects are chosen based on their potential to mature and/or transition software engineering practices, develop information that will help in deciding whether further work is worth funding, and set new directions for SEI work. This report describes the IRAD projects that were conducted during fiscal year 2007 (October 2006 through September 2007)

Results of SEI Independent Research and Development Projects

The Software Engineering Institute (SEI) annually undertakes several independent research and development (IRAD) projects. These projects serve to (1) support feasibility studies investigating whether further work by the SEI would be of potential benefit and (2) support further exploratory work to determine whether there is sufficient value in eventually funding the feasibility study work as an SEI initiative. Projects are chosen based on their potential to mature and/or transition software engineering practices, develop information that will help in deciding whether further work is worth funding, and set new directions for SEI work. This report describes the IRAD projects that were conducted during fiscal year 2009 (October 2008 through September 2009)

Results of SEI Independent Research and Development Projects (FY 2010)

The Software Engineering Institute (SEI) annually undertakes several independent research and development (IRAD) projects. These projects serve to (1) support feasibility studies investigating whether further work by the SEI would be of potential benefit and (2) support further exploratory work to determine whether there is sufficient value in eventually funding the feasibility study work as an SEI initiative. Projects are chosen based on their potential to mature and/or transition software engineering practices, develop information that will help in deciding whether further work is worth funding, and set new directions for SEI work. This report describes the IRAD projects that were conducted during fiscal year 2010 (October 2009 through September 2010).</p