Software Verification Process Research Articles

Verification of Air Data Computer Software using Formal Methods

With the rapid development of airborne system and software, the requirement of software’s robustness, adaptability and reliability improves continually. Failure of software function may cause severe property loss and personnel casualties. Formal methods are mathematically based techniques for the specification, development, and verification of software aspects of digital systems that have obvious advantages in improving safety and reliability of airborne software. This paper takes Air Data Computer software as an example for formal verification in the whole software development process including requirements process, design process, coding process and integration process to demonstrate a set of formal methods application in the airborne software verification process.

A Software Verification Approach That Complies with DO-178B Certification Rules on UAV’s Flight Control Computer

In this paper, the verification approach developed in accordance with the DO-178B certification requirements of the software of the Unmanned Aerial Vehicle’s (UAV) Flight Control Computer (FCC) and the lessons learned from this approach are presented. The software verification process is a process that is used to verify how the aircraft's flight control computer behaves according to specified requirements and is used to verify that it does not produce unexpected results. The paper will first describe the software architecture, and then the types of tests developed in accordance with the software architecture. Then, test levels will be compared according to different testing parameters. Afterwards, the information regarding the management of test cases will be reviewed in detail with their different scenarios. The traceability controls and the importance of using traceability while writing the test cases and how to blend a traceability inside a test case will be explained. The studies on structural coverage analysis will be covered in a different section. This whole process can be made automated. To help automate the process, various tools are used. These tools also need to be tested, meaning they need to be qualified. Section 8 talks about this. Finally, lessons learned from the DO-178B certification process will be presented at the end of the paper.

Model-driven Framework for Requirement Traceability

In software development, requirements traceability is often mandated. It is important to apply to support various software development activities like result evaluation, regression testing and coverage analysis. Model-Driven Testing is one approach to provide a way to verify and validate requirements. However, it has many challenges in test generation in addition to the creation and maintenance of traceability information across test-related artifacts. This paper presents a model-based methodology for requirements traceability that relies on leveraging model transformation traceability techniques to achieve compliance with DO-178C standard as defined in the software verification process. This paper also demonstrates and evaluates the proposed methodology using avionics case studies focusing on the functional aspects of the requirements specified with the UCM (Use Case Maps) modeling language.

Оцінка програмного забезпечення систем залізничного транспорту станційного рівня на відповідність вимогам українських стандартів

The purpose of this article is to find effective methods for assessing and proving the functional safety of software at the station level railway control systems. Adaptation of experience and development of a common approach to the software verification process. Method. To achieve this purpose the analysis of current regulatory documents was conducted. An adaptation of the existing experience in performing the conformity assessment of information and control systems important for the safety of nuclear power plants was carried out. All this allowed to determine the general requirements and methods of evaluation of software for various purpose. Results. Based on the results of the analysis of the current normative documents, the procedure for evaluating the software of systems of various purposes has been implemented in the TCC of LTD RPI HARTRON-ARKOS. Scientific novelty. This article formulates proposals for the extension of the standards of DSTU 4178 in the part of the assessment and proof of functional safety of software at the station level railway control systems. At the same time, the general requirements and methods of evaluation of software for different purposes, given in the current standards, were taken into account. Practical importance. The proposed approach of railway system software evaluation greatly extends the requirements of DSTU 4178 and facilitates the development and implementation of new, more effective software verification methods.

Development of an online assessment based on the Shareable Content Object Reference Model (SCORM) to optimize the use of BeSmart UNY

This study aimed at developing an Online Assessment based on the Shareable Content Object Reference Model (SCORM) package. This study focused on: (1) obtaining an online assessment design based on SCORM package for the subject of Medical Instrumentation and Electronics based on needs analysis; (2) examining the functionality of the developed online assessment and (3) analyzing the usability of the developed online assessment. This software development process used the ADDIE development model. The testing stage of this study was conducted to verify and to validate the software. The software verification process was performed with functionality testing by media and material experts, and usability testing by users. The results indicated that: (1) it was obtained the design of an online assessment based on SCORM package for the subject of Medical Instrumentation and Electronics, including an online assessment in Besmart packed with SCORM Packages in the form of quiz integration (multiple-choice, short answer, true or false, drag and drop questions); (2) the functionality testing by material experts with a score of 3.88 and a media expert with a score of 4.16 suggested that the developed online assessment was feasible in the aspect of functionality; (3) usability testing by users achieved the score of 3.88 indicating that the developed online assessment was feasible in the aspect of usability.

Understanding Counterexamples for Relational Properties with DIbugger

Software verification is a tedious process that involves the analysis of multiple failed verification attempts, and adjustments of the program or specification. This is especially the case for complex requirements, e.g., regarding security or fairness, when one needs to compare multiple related runs of the same software. Verification tools often provide counterexamples consisting of program inputs when a proof attempt fails, however it is often not clear why the reported counterexample leads to a violation of the checked property. In this paper, we enhance this aspect of the software verification process by providing DIbugger, a tool for analyzing counterexamples of relational properties, allowing the user to debug multiple related programs simultaneously.

Software verification process and methodology for the development of FPGA-based engineered safety features system

Verification process is very important for the new development or re-engineering process for Instrumentation and Control (I&C) in Nuclear Power Plant (NPP). Due to the fact that the Engineered Safety Feature-Component Control System (ESF-CCS) is safety critical system, it is necessary to specify a systematic approach to verify the performance of development design. For this verification process, a system engineering approach is used and refers to the software design life cycle to verify the VHDL code in the implementation of Field Programmable Gate Array (FPGA)-based ESF-CCS. Although FPGA does not use software, however, FPGA needs a Hardware Description Language (HDL) to describe digital and mixed-signal for an integrated system. Therefore, the VHDL code should be verified to make sure that this code level will not cause an error for the FPGA-based system, especially for ESF-CCS development. The verification method is started by looking at the requirements analysis, verification of the outputs of the design by develop software testing to verify the reliability of the code which is to support the FPGA-based ESF-CCS. White Box testing is used for software testing to demonstrate the responds from the VHDL code, whether the design is success or not, and the coverage test is at 100% coverage state. In addition, the Static Timing Analysis (STA) is applied to check the delay time. Once all verification steps have been performed, then the results of the design can be validated. In this paper, FPGA-based ESF-CCS using VHDL code is verified.

Satisfying DO-178C Structural Coverage Objectives

Structural coverage analysis is an important task for the development of safety-critical systems. In particular, structural coverage analysis is one of the objectives specified in RTCA DO-178C for the airborne software verification process. Structural coverage analysis is normally supported by the tools that collect coverage information in the course of test execution. This paper concerns with the problems and methods of structural coverage collecting in order to specify the required functionality of structural coverage collecting tools, which is necessary to provide their compliance with the DO-178C objectives.

Formal Verification With Frama-C: A Case Study in the Space Software Domain

With the increasing importance of software in the aerospace field, as evidenced by its growing size and complexity, a rigorous and reliable software verification and validation process must be applied to ensure conformance with the strict requirements of this software. Although important, traditional validation activities such as testing and simulation can only provide a partial verification of behavior in critical real-time software systems, and thus, formal verification is an alternative to complement these activities. Two useful formal software verification approaches are deductive verification and abstract interpretation, which analyze programs statically to identify defects. This paper explores abstract interpretation and deductive verification by employing Frama-C’s value analysis and Jessie plug-ins to verify embedded aerospace control software. The results indicate that both approaches can be employed in a software verification process to make software more reliable.

Certification and Software Verification Considerations for Autonomous Unmanned Aircraft

Software verification for highly automatic unmanned aerial vehicles is not only a problem itself, it is furthermore constrained by certification standards and regulatory rules. These, however, are themselves still under development. As a top-level view, the current status of unmanned aerial vehicle verification, certification, and regulation is addressed and corresponding challenges are discussed. From a low-level view, this work presents the processes and tools that were established for the software development, verification, and validation of the unmanned rotorcraft software testbed ARTIS. Large efforts have been put into the software verification process to cope with the growing complexity of the autonomous system and the validation of the software behavior. Automated tests drive the development of the mission planning, mission management, and sensor fusion systems. High-level behavior is tested by complex simulation scenarios. To connect the aforementioned top- and low-level views, a comparison between the RTCA DO-178C standard (“Software Considerations in Airborne Systems and Equipment Certification”) and corresponding ARTIS software development practices is elaborated to assess the efforts that would be necessary for a small research team to develop software according to the standard. It shows that the currently used practices are not incompatible, but there are still some gaps to the desired level of compliance.

Particularities of Verification Processes for Distributed Informatics Applications

This paper presents distributed informatics applications and characteristics of their development cycle. It defines the concept of verification and there are identified the differences from software testing. Particularities of the software testing and software verification processes are described. The verification steps and necessary conditions are presented and there are established influence factors of quality verification. Software optimality verification is analyzed and some metrics are defined for the verification process.Keywords: Distributed Informatics Applications, Software Testing, Software Verification, Verification Process, Software Optimality(ProQuest: ... denotes formulae omitted.)1 Characteristics of Distributed Informatics ApplicationsDistributed informatics applications are software constructions that are based on architectures whose components, through interaction, realize allocations of resources in real time. Distributed informatics applications include:- a heterogeneous group of users, having many elements that, through interaction, solve their well-defined problems, as data entry volume, sequence operations that activates and with concrete results that marks the success of performing the interaction or the need to retake some components from the operations chain specifying the cause and the manner of disposal: after a few replays each user successfully completes the interaction getting the message meaning that his problem has been solved correctly and completely;- dynamic definition of computer network through which is realized the messages transfer of user exempted in the ground indefinitely, the only restrictions being those related to hardware resources that ensure compatibility with data acquisition system and connection performance;- conducting an achievements cycle that includes steps, such as: defining the target group and setting its size; defining the set of distinct problems, which are subject to processing; in this respect for each problem are used appropriate definition tools to reduce the risk of sub-definitions or supra-definitions, situations attracting reversals of prior steps when minuses of information in the case of sub-definitions, or the excess of information, in the case of supra-definition of the problem, generate effects that lead to discontinuation of the development cycle with the impossibility to pass to the next stage; the stage of clear specifications, consistent, the development stage of informatics solutions variants accompanied by performance estimation models requires choosing the suitable variant against the criterion with which the multiplication effects is managed at the moment of implementation; the code elaboration stage as optimal resource allocation process, knowing that the instructions, data structures defining mechanism and building of sequences procedures must be understood as infinite resource use, but which differ from each other in terms of performance criteria of informatics applications, taken as a whole; the testing stage [1] play a very special role for the distributed informatics applications because these operates independently of the developer; the user has limited possibilities to manage uncontrolled situations resulting from existing errors in procedures that allocate resources wrongly or generates random processing behavior, which ultimately creates users discomfort (elaboration, documentation, implementation).Modern distributed informatics applications are investments, so they include:- the investor who pays the development of the distributed informatics application;- staffproviding application development;- staffensuring exploitation management;- users that solves the problem with the distributed informatics application, which becomes service provider;- from the amounts transferred by the users to other destinations, a part returns to the investor, a part to the management of the application and the investment is recovered, and those who ensure the management have their profit. …

Using Bounded Model Checking for Coverage Analysis of Safety-Critical Software in an Industrial Setting

Testing and Bounded Model Checking (BMC) are two techniques used in Software Verification for bug-hunting. They are expression of two different philosophies: testing is used on the compiled code and it is more suited to find errors in common behaviors, while BMC is used on the source code to find errors in uncommon behaviors of the system. Nowadays, testing is by far the most used technique for software verification in industry: it is easy to use and even when no error is found, it can release a set of tests certifying the (partial) correctness of the compiled system. In the case of safety critical software, in order to increase the confidence of the correctness of the compiled system, it is often required that the provided set of tests covers 100% of the code. This requirement, however, substantially increases the costs associated to the testing phase, since it often involves the manual generation of tests. In this paper we show how BMC can be productively applied to the Software Verification process in industry. In particular, we show how to productively use a Bounded Model Checker for C programs (CBMC) as an automatic test generator for the Coverage Analysis of Safety Critical Software. In particular, we experimented CBMC on a subset of the modules of the European Train Control System (ETCS) of the European Rail Traffic Management System (ERTMS) source code, an industrial system for the control of the traffic railway, provided by Ansaldo STS. The Code of the ERTMS/ETCS, with thousands of lines, has been used as trial application with CBMC obtaining a set of tests satisfying the target 100% code coverage, requested by the CENELEC EN50128 guidelines for software development of safety critical systems. The use of CBMC for test generation led to a dramatic increase in the productivity of the entire Software Development process by substantially reducing the costs of the testing phase. To the best of our knowledge, this is the first time that BMC techniques have been used in an industrial setting for automatically generating tests achieving full coverage of Safety-Critical Software. The positive results demonstrate the maturity of Bounded Model Checking techniques for automatic test generation in industry.

Trusting Computers Through Trusting Humans

This article considers the question of how we may trust automatically generated program code. The code walkthroughs and inspections of software engineering mimic the ways that mathematicians go about assuring themselves that a mathematical proof is true. Mathematicians have difficulty accepting a computer generated proof because they cannot go through the social processes of trusting its construction. Similarly, those involved in accepting a proof of a computer system or computer generated code cannot go through their traditional processes of trust. The process of software verification is bound up in software quality assurance procedures, which are themselves subject to commercial pressures. Quality standards, including military standards, have procedures for human trust designed into them. An action research case study of an avionics system within a military aircraft company illustrates these points, where the software quality assurance (SQA) procedures were incommensurable with the use of automatically generated code.

A High-Level Language Implementation of an Engine Control Strategy

An engine control program which was originally written in assembly language and which is currently used in production vehicles, has been rewritten using a high-level language specifically designed for automotive control applications. The language and the control strategy are described and the two program implementations are compared in various ways. The high-level language implementation was used to operate a vehicle, and was tested using the software verification process which is used for all production engine control software at Ford Motor Company, Dearborn, Michigan.