Asim Abdulkhaleq | Universität Stuttgart (original) (raw)

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Papers by Asim Abdulkhaleq

Research paper thumbnail of Detection of Functionally Similar Code Clones: Data, Analysis Software, Benchmark

Research paper thumbnail of On the Relationship of Inconsistent Software Clones and Faults: An Empirical Study

2016 IEEE 23rd International Conference on Software Analysis, Evolution, and Reengineering (SANER), 2016

Research paper thumbnail of Open tool support for System-Theoretic Process Analysis

Research paper thumbnail of How are functionally similar code clones syntactically different? An empirical study and a benchmark

PeerJ Computer Science, 2016

Research paper thumbnail of A Comprehensive Safety Engineering Approach for Software-Intensive Systems Based on STPA

Procedia Engineering, 2015

Research paper thumbnail of A controlled experiment for the empirical evaluation of safety analysis techniques for safety-critical software

Context: Today's safety critical systems are increasingly reliant on software. Software becomes r... more Context: Today's safety critical systems are increasingly reliant on software. Software becomes responsible for most of the critical functions of systems. Many different safety analysis techniques have been developed to identify hazards of systems. FTA and FMEA are most commonly used by safety analysts. Recently, STPA has been proposed with the goal to better cope with complex systems including software. Objective: This research aimed at comparing quantitatively these three safety analysis techniques with regard to their effectiveness, applicability, understandability, ease of use and efficiency in identifying software safety requirements at the system level. Method: We conducted a controlled experiment with 21 master and bachelor students applying these three techniques to three safety-critical systems: train door control, anti-lock braking and traffic collision and avoidance. Results: The results showed that there is no statistically significant difference between these techniques in terms of applicability, understandability and ease of use, but a significant difference in terms of effectiveness and efficiency is obtained. Conclusion: We conclude that STPA seems to be an effective method to identify software safety requirements at the system level. In particular, STPA addresses more different software safety requirements than the traditional techniques FTA and FMEA, but STPA needs more time to carry out by safety analysts with little or no prior experience.

Research paper thumbnail of Integrated Safety Analysis Using Systems-Theoretic Process Analysis and Software Model Checking

Lecture Notes in Computer Science, 2015

Research paper thumbnail of Experiment Material

Research paper thumbnail of Experiences with Applying STPA to Software-Intensive Systems in the Automotive Domain

Hazard analysis is one of the most important elements in developing safe-critical systems. STPA (... more Hazard analysis is one of the most important elements in developing safe-critical systems. STPA (Systems-Theoretic Process Analysis) is a modern technique based on the new accident causation model STAMP (System-Theoretic Accident Model and Process) for analyzing hazard and safety issues, which can be applied early in the design process of a system to achieve an acceptable risk level. We have applied STPA to a well-known example of safety-critical systems in the automotive industries: Adaptive Cruise Control (ACC). The results of the application of STPA to our case study and the limitations and difficulties of applying STPA are presented.

Research paper thumbnail of Integrating State Machine Analysis with System-Theoretic Process Analysis

Safety becomes a critical aspect for software-intensive systems in different applications areas. ... more Safety becomes a critical aspect for software-intensive systems in different applications areas. Many hazard analysis techniques are proposed and used to investigate system design models to elicit hazards and design flaws. STPA (System-Theoretic Process Analysis) is a modern hazard analysis technique, which is based on a new systems-theoretic model of accidents for large and complex systems. With STPA, the system is viewed as interacting control loops and the accidents are considered as results from inadequate enforcement of safety constraints in design, development and operation. STPA still needs appropriate diagrammatic notations to represent the relation between the process model variables, control actions and hazards. For this purpose, we propose to integrate state machine analysis with STPA to provide a suitable notation of arguments between the states of controllers, control actions and hazards.

Research paper thumbnail of A-STPA: An Open Tool Support for System-Theoretic Process Analysis

STPA (System-Theoretic Process Analysis) is a new hazard analysis technique which builds on STAMP... more STPA (System-Theoretic Process Analysis) is a new hazard analysis technique which builds on STAMP, a process and accident model using concepts of system and control theory. In this paper, we present A-STPA an open tool to help transform STPA to an executable STPA which automates the activities of STPA. We develop the A-STPA tool to assist safety analysts in performing STPA. Moreover, it will give the safety analysts different views on the STPA hazard analysis process. We discuss the design of the tool and illustrate its usage. So far, it is still an early version but it can already help the safety analysts in avoiding consistency defects. We are confident that A-STPA will become a powerful tool support for STPA.

Research paper thumbnail of XSTAMPP: An eXtensible STAMP Platform As Tool Support for Safety Engineering

STPA (Systems-Theoretic Processes Analysis) is a new hazard analysis technique based on STAMP. ST... more STPA (Systems-Theoretic Processes Analysis) is a new hazard analysis technique based on STAMP. STPA is already being used in different industrial domains (e.g. space, aviation, medical or automotive). To support the application of STPA and make using STPA more efficient, we developed an open tool called A-STPA. However, the current usage of A-STPA by safety analysts in different areas shows a number of shortcomings in terms of documenting unsafe control actions, drawing different levels of control structure diagrams, docu-menting the causal factors in STPA Step 2 and supporting the application of STPA in different areas. In this paper, we present an extensible STAMP platform called XSTAMPP as tool support designed specifically to serve the widespread adoption and use of STPA in different areas, to facilitate STPA application to different systems and to be easily extended to include different requirements and features. Moreover, XSTAMPP has the potential to be extended in the future ...

Research paper thumbnail of A controlled experiment for the empirical evaluation of safety analysis techniques for safety-critical software

Proceedings of the 19th International Conference on Evaluation and Assessment in Software Engineering - EASE '15, 2015

Context: Today's safety critical systems are increasingly reliant on software. Software becomes r... more Context: Today's safety critical systems are increasingly reliant on software. Software becomes responsible for most of the critical functions of systems. Many different safety analysis techniques have been developed to identify hazards of systems. FTA and FMEA are most commonly used by safety analysts. Recently, STPA has been proposed with the goal to better cope with complex systems including software. Objective: This research aimed at comparing quantitatively these three safety analysis techniques with regard to their effectiveness, applicability, understandability, ease of use and efficiency in identifying software safety requirements at the system level. Method: We conducted a controlled experiment with 21 master and bachelor students applying these three techniques to three safety-critical systems: train door control, anti-lock braking and traffic collision and avoidance. Results: The results showed that there is no statistically significant difference between these techniques in terms of applicability, understandability and ease of use, but a significant difference in terms of effectiveness and efficiency is obtained. Conclusion: We conclude that STPA seems to be an effective method to identify software safety requirements at the system level. In particular, STPA addresses more different software safety requirements than the traditional techniques FTA and FMEA, but STPA needs more time to carry out by safety analysts with little or no prior experience.

Research paper thumbnail of A Software Safety Verification Method Based on System-Theoretic Process Analysis

Lecture Notes in Computer Science, 2014

ABSTRACT Modern safety-critical systems are increasingly reliant on software. Software safety is ... more ABSTRACT Modern safety-critical systems are increasingly reliant on software. Software safety is an important aspect in developing safety-critical systems, and it must be considered in the context of the system level into which the software will be embedded. STPA (System-Theoretic Process Analysis) is a modern safety analysis approach which aims to identify the potential hazardous causes in complex safety-critical systems at the system level. To assure that these hazardous causes of an unsafe software's behaviour cannot happen, safety verification involves demonstrating whether the software fulfills those safety requirements and will not result in a hazardous state. We propose a method for verifying of software safety requirements which are derived at the system level to provide evidence that the hazardous causes cannot occur (or reduce the associated risk to a low acceptable level). We applied the method to a cruise control prototype to show the feasibility of the proposed method.

Research paper thumbnail of Neural Network Based Microcontroller Operated Intelligent Vehicle System

Abstract - Today a fast real-time and robust automatic vehicle system is required to increase dri... more Abstract - Today a fast real-time and robust automatic vehicle system is required to increase driving safety as the manned driving is getting extremely numbered, so are those of traffic jams, bad, dangerous and rough drivers and more importantly, accidents. Automatic recognition of traffic signs is also important for automated intelligent driving vehicle or driver assistance systems. This paper presents a new technique for object recognition and control the vehicle thereby. A combination of image processing and artificial neural network has been used for extraction and recognition of the boundaries in captured noisy images. A car is chosen to move towards some defined directions. Direction of the car in a certain moment is a subject of sensing. This sensing is fed to the car to implement image processing techniques and some matching principles by means of artificial neural network. The microcontroller operating the car receives the data via serial port and drives it
by analyzing the data. Experimental results demonstrating the performance of the proposed technique are also presented. Performance analysis shows that the applied technique is able to execute well on a low performance CPU without requiring significant additional CPU resources.

Research paper thumbnail of Detection of Functionally Similar Code Clones: Data, Analysis Software, Benchmark

Research paper thumbnail of On the Relationship of Inconsistent Software Clones and Faults: An Empirical Study

2016 IEEE 23rd International Conference on Software Analysis, Evolution, and Reengineering (SANER), 2016

Research paper thumbnail of Open tool support for System-Theoretic Process Analysis

Research paper thumbnail of How are functionally similar code clones syntactically different? An empirical study and a benchmark

PeerJ Computer Science, 2016

Research paper thumbnail of A Comprehensive Safety Engineering Approach for Software-Intensive Systems Based on STPA

Procedia Engineering, 2015

Research paper thumbnail of A controlled experiment for the empirical evaluation of safety analysis techniques for safety-critical software

Context: Today's safety critical systems are increasingly reliant on software. Software becomes r... more Context: Today's safety critical systems are increasingly reliant on software. Software becomes responsible for most of the critical functions of systems. Many different safety analysis techniques have been developed to identify hazards of systems. FTA and FMEA are most commonly used by safety analysts. Recently, STPA has been proposed with the goal to better cope with complex systems including software. Objective: This research aimed at comparing quantitatively these three safety analysis techniques with regard to their effectiveness, applicability, understandability, ease of use and efficiency in identifying software safety requirements at the system level. Method: We conducted a controlled experiment with 21 master and bachelor students applying these three techniques to three safety-critical systems: train door control, anti-lock braking and traffic collision and avoidance. Results: The results showed that there is no statistically significant difference between these techniques in terms of applicability, understandability and ease of use, but a significant difference in terms of effectiveness and efficiency is obtained. Conclusion: We conclude that STPA seems to be an effective method to identify software safety requirements at the system level. In particular, STPA addresses more different software safety requirements than the traditional techniques FTA and FMEA, but STPA needs more time to carry out by safety analysts with little or no prior experience.

Research paper thumbnail of Integrated Safety Analysis Using Systems-Theoretic Process Analysis and Software Model Checking

Lecture Notes in Computer Science, 2015

Research paper thumbnail of Experiment Material

Research paper thumbnail of Experiences with Applying STPA to Software-Intensive Systems in the Automotive Domain

Hazard analysis is one of the most important elements in developing safe-critical systems. STPA (... more Hazard analysis is one of the most important elements in developing safe-critical systems. STPA (Systems-Theoretic Process Analysis) is a modern technique based on the new accident causation model STAMP (System-Theoretic Accident Model and Process) for analyzing hazard and safety issues, which can be applied early in the design process of a system to achieve an acceptable risk level. We have applied STPA to a well-known example of safety-critical systems in the automotive industries: Adaptive Cruise Control (ACC). The results of the application of STPA to our case study and the limitations and difficulties of applying STPA are presented.

Research paper thumbnail of Integrating State Machine Analysis with System-Theoretic Process Analysis

Safety becomes a critical aspect for software-intensive systems in different applications areas. ... more Safety becomes a critical aspect for software-intensive systems in different applications areas. Many hazard analysis techniques are proposed and used to investigate system design models to elicit hazards and design flaws. STPA (System-Theoretic Process Analysis) is a modern hazard analysis technique, which is based on a new systems-theoretic model of accidents for large and complex systems. With STPA, the system is viewed as interacting control loops and the accidents are considered as results from inadequate enforcement of safety constraints in design, development and operation. STPA still needs appropriate diagrammatic notations to represent the relation between the process model variables, control actions and hazards. For this purpose, we propose to integrate state machine analysis with STPA to provide a suitable notation of arguments between the states of controllers, control actions and hazards.

Research paper thumbnail of A-STPA: An Open Tool Support for System-Theoretic Process Analysis

STPA (System-Theoretic Process Analysis) is a new hazard analysis technique which builds on STAMP... more STPA (System-Theoretic Process Analysis) is a new hazard analysis technique which builds on STAMP, a process and accident model using concepts of system and control theory. In this paper, we present A-STPA an open tool to help transform STPA to an executable STPA which automates the activities of STPA. We develop the A-STPA tool to assist safety analysts in performing STPA. Moreover, it will give the safety analysts different views on the STPA hazard analysis process. We discuss the design of the tool and illustrate its usage. So far, it is still an early version but it can already help the safety analysts in avoiding consistency defects. We are confident that A-STPA will become a powerful tool support for STPA.

Research paper thumbnail of XSTAMPP: An eXtensible STAMP Platform As Tool Support for Safety Engineering

STPA (Systems-Theoretic Processes Analysis) is a new hazard analysis technique based on STAMP. ST... more STPA (Systems-Theoretic Processes Analysis) is a new hazard analysis technique based on STAMP. STPA is already being used in different industrial domains (e.g. space, aviation, medical or automotive). To support the application of STPA and make using STPA more efficient, we developed an open tool called A-STPA. However, the current usage of A-STPA by safety analysts in different areas shows a number of shortcomings in terms of documenting unsafe control actions, drawing different levels of control structure diagrams, docu-menting the causal factors in STPA Step 2 and supporting the application of STPA in different areas. In this paper, we present an extensible STAMP platform called XSTAMPP as tool support designed specifically to serve the widespread adoption and use of STPA in different areas, to facilitate STPA application to different systems and to be easily extended to include different requirements and features. Moreover, XSTAMPP has the potential to be extended in the future ...

Research paper thumbnail of A controlled experiment for the empirical evaluation of safety analysis techniques for safety-critical software

Proceedings of the 19th International Conference on Evaluation and Assessment in Software Engineering - EASE '15, 2015

Context: Today's safety critical systems are increasingly reliant on software. Software becomes r... more Context: Today's safety critical systems are increasingly reliant on software. Software becomes responsible for most of the critical functions of systems. Many different safety analysis techniques have been developed to identify hazards of systems. FTA and FMEA are most commonly used by safety analysts. Recently, STPA has been proposed with the goal to better cope with complex systems including software. Objective: This research aimed at comparing quantitatively these three safety analysis techniques with regard to their effectiveness, applicability, understandability, ease of use and efficiency in identifying software safety requirements at the system level. Method: We conducted a controlled experiment with 21 master and bachelor students applying these three techniques to three safety-critical systems: train door control, anti-lock braking and traffic collision and avoidance. Results: The results showed that there is no statistically significant difference between these techniques in terms of applicability, understandability and ease of use, but a significant difference in terms of effectiveness and efficiency is obtained. Conclusion: We conclude that STPA seems to be an effective method to identify software safety requirements at the system level. In particular, STPA addresses more different software safety requirements than the traditional techniques FTA and FMEA, but STPA needs more time to carry out by safety analysts with little or no prior experience.

Research paper thumbnail of A Software Safety Verification Method Based on System-Theoretic Process Analysis

Lecture Notes in Computer Science, 2014

ABSTRACT Modern safety-critical systems are increasingly reliant on software. Software safety is ... more ABSTRACT Modern safety-critical systems are increasingly reliant on software. Software safety is an important aspect in developing safety-critical systems, and it must be considered in the context of the system level into which the software will be embedded. STPA (System-Theoretic Process Analysis) is a modern safety analysis approach which aims to identify the potential hazardous causes in complex safety-critical systems at the system level. To assure that these hazardous causes of an unsafe software's behaviour cannot happen, safety verification involves demonstrating whether the software fulfills those safety requirements and will not result in a hazardous state. We propose a method for verifying of software safety requirements which are derived at the system level to provide evidence that the hazardous causes cannot occur (or reduce the associated risk to a low acceptable level). We applied the method to a cruise control prototype to show the feasibility of the proposed method.

Research paper thumbnail of Neural Network Based Microcontroller Operated Intelligent Vehicle System

Abstract - Today a fast real-time and robust automatic vehicle system is required to increase dri... more Abstract - Today a fast real-time and robust automatic vehicle system is required to increase driving safety as the manned driving is getting extremely numbered, so are those of traffic jams, bad, dangerous and rough drivers and more importantly, accidents. Automatic recognition of traffic signs is also important for automated intelligent driving vehicle or driver assistance systems. This paper presents a new technique for object recognition and control the vehicle thereby. A combination of image processing and artificial neural network has been used for extraction and recognition of the boundaries in captured noisy images. A car is chosen to move towards some defined directions. Direction of the car in a certain moment is a subject of sensing. This sensing is fed to the car to implement image processing techniques and some matching principles by means of artificial neural network. The microcontroller operating the car receives the data via serial port and drives it
by analyzing the data. Experimental results demonstrating the performance of the proposed technique are also presented. Performance analysis shows that the applied technique is able to execute well on a low performance CPU without requiring significant additional CPU resources.