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Punnekkat, SasikumarORCID iD iconorcid.org/0000-0001-5269-3900
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Publications (10 of 114) Show all publications
Baumgart, S., Fröberg, J. & Punnekkat, S. (2018). Can STPA be used for a System-of-Systems? Experiences from an Automated Quarry Site. In: 4th IEEE International Symposium on Systems Engineering, ISSE 2018 - Proceedings: . Paper presented at 4th IEEE International Symposium on Systems Engineering, ISSE 2018; Rome Marriott Park HotelRoma; Italy; 1 October 2018 through 3 October 2018; Category numberCFP18SYM-ART; Code 143143. (4), Article ID 8544433.
Open this publication in new window or tab >>Can STPA be used for a System-of-Systems? Experiences from an Automated Quarry Site
2018 (English)In: 4th IEEE International Symposium on Systems Engineering, ISSE 2018 - Proceedings, 2018, no 4, article id 8544433Conference paper, Published paper (Refereed)
Abstract [en]

Automation is becoming prevalent in more and more industrial domains due to the potential benefits in cost reduction as well as the new approaches/solutions they enable. When machines are automated and utilized in system-of-systems, a thorough analysis of potential critical scenarios is necessary to derive appropriate design solutions that are safe as well. Hazard analysis methods like PHA, FTA or FMEA help to identify and follow up potential risks for the machine operators or bystanders and are well-established in the development process for safety critical machinery. However, safety certified individual machines can no way guarantee safety in the context of system-of-systems since their integration and interactions could bring forth newer hazards. Hence it is paramount to understand the application sce- narios of the system-of-systems and to apply a structured method to identify all potential hazards. In this paper, we 1) provide an overview of proposed hazard analysis methods for system-of- systems, 2) describe a case from construction equipment domain, and 3) apply the well-known System-Theoretic Process Analysis (STPA)f to our case. Our experiences during the case study and the analysis of results clearly point out certain inadequacies of STPA in the context of system-of-systems and underlines the need for the development of improved techniques for safety analysis of system-of-systems.

Keywords
Hazard Analysis and Risk Assessment, System- of-Systems, Autonomous Machines, STPA, Safety
National Category
Engineering and Technology Computer Systems
Identifiers
urn:nbn:se:mdh:diva-41719 (URN)10.1109/SysEng.2018.8544433 (DOI)2-s2.0-85059989681 (Scopus ID)
Conference
4th IEEE International Symposium on Systems Engineering, ISSE 2018; Rome Marriott Park HotelRoma; Italy; 1 October 2018 through 3 October 2018; Category numberCFP18SYM-ART; Code 143143
Projects
ITS-EASY Post Graduate School for Embedded Software and Systems
Available from: 2018-12-21 Created: 2018-12-21 Last updated: 2019-01-31Bibliographically approved
Davis, R., Thekilakkattil, A., Gettings, O., Dobrin, R., Punnekkat, S. & Chen, J.-J. (2018). Exact Speedup Factors and Sub-Optimality for Non-Preemptive Scheduling. Real-time systems, 208-246
Open this publication in new window or tab >>Exact Speedup Factors and Sub-Optimality for Non-Preemptive Scheduling
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2018 (English)In: Real-time systems, ISSN 0922-6443, E-ISSN 1573-1383, p. 208-246Article in journal (Refereed) Published
Abstract [en]

Fixed priority scheduling is used in many real-time systems; however, both preemptive and non-preemptive variants (FP-P and FP-NP) are known to be sub-optimal when compared to an optimal uniprocessor scheduling algorithm such as preemptive Earliest Deadline First (EDF-P). In this paper, we investigate the sub-optimality of xed priority non-preemptive scheduling. Speci cally, we derive the exact processor speed-up factor required to guarantee the feasibility under FP-NP (i.e. schedulablability assuming an optimal priority assignment) of any task set that is feasible under EDF-P. As a consequence of this work, we also derive a lower bound on the sub-optimality of non-preemptive EDF (EDF-NP). As this lower bound matches a recently published upper bound for the same quantity, it closes the exact sub-optimality for EDF-NP. It is known that neither preemptive, nor non-preemptive xed priority scheduling dominates the other, in other words, there are task sets that are feasible on a processor of unit speed under FP-P that are not feasible under FP-NP and vice-versa. Hence comparing these two algorithms, there are non-trivial speedup factors in both directions. We derive the exact speed-up factor required to guarantee the FP-NP feasibility of any FP-P feasible task set. Further, we derive the exact speed-up factor required to guarantee FP-P feasibility of any constrained-deadline FP-NP feasible task set.

Keywords
real-time uniprocessor resource augmentation speedupfactor sub-optimality non-preemptive scheduling preemptive scheduling EDF xed priority
National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-37337 (URN)10.1007/s11241-017-9294-3 (DOI)000419955500007 ()2-s2.0-85032335776 (Scopus ID)
Available from: 2017-11-28 Created: 2017-11-28 Last updated: 2018-01-26Bibliographically approved
Gutiérrez, M., Ademaj, A., Steiner, W., Dobrin, R. & Punnekkat, S. (2018). Self-Configuration of IEEE 802.1 TSN Networks. In: : . Paper presented at 22nd IEEE International Conference on Emerging Technologies And Factory Automation (ETFA, Limassol, CYPRUS, SEP 12-15, 2017. , Article ID F134116.
Open this publication in new window or tab >>Self-Configuration of IEEE 802.1 TSN Networks
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2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Configuration processes of real-time networks are costly both in terms of time and engineering effort and require the system to be shutdown during the reconfiguration phase thus resulting in significant down time as well. The convergence of IT/OT technologies is bringing a whole world of possibilities for the configuration and management of real-time networks for the automation industry. With software defined networking (SDN) features like the separation of the data and control plane and standards like IEEE 802.1 developed with the goal of adding deterministic capabilities to traditionally dynamic switched Ethernet networks, the plug and play paradigm is almost around the corner. In this paper, we go one step further and start looking into the self-configuration of real-time networks. To achieve that we propose to introduce a Configuration Agent in the network, an entity that continuously monitors the network to detect changes and automatically update the configuration to adapt to such changes while maintaining desired quality of service. We present here the complete framework for the Configuration Agent that will provide self-configuration capabilities to real-time networks. The proposed framework has IEEE 802.1 as its core, but also shows how the set of standards need to be extended in order to achieve the self-configuration requirements. Concretely we examine the role of existing communication protocols like NETCONF and OPC-UA and propose the essential ingredients (managed objects) for a YANG model for the learning aspects in the bridges, including different working modes.

Series
IEEE International Conference on Emerging Technologies and Factory Automation-ETFA
National Category
Embedded Systems
Identifiers
urn:nbn:se:mdh:diva-37100 (URN)10.1109/ETFA.2017.8247597 (DOI)000427812000032 ()2-s2.0-85044449708 (Scopus ID)9781509065059 (ISBN)
Conference
22nd IEEE International Conference on Emerging Technologies And Factory Automation (ETFA, Limassol, CYPRUS, SEP 12-15, 2017
Available from: 2017-10-19 Created: 2017-10-19 Last updated: 2018-04-05Bibliographically approved
Jaradat, O. & Punnekkat, S. (2018). Using Safety Contracts to Verify Design Assumptions During Runtime. In: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Volume 10873: . Paper presented at 23rd International Conference on Reliable Software Technologies, Ada-Europe 2018, 18-22 June 2018, Lisbon, Portugal (pp. 3-18).
Open this publication in new window or tab >>Using Safety Contracts to Verify Design Assumptions During Runtime
2018 (English)In: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Volume 10873, 2018, p. 3-18Conference paper, Published paper (Refereed)
Abstract [en]

A safety case comprises evidence and argument justifying how each item of evidence supports claims about safety assurance. Supporting claims by untrustworthy or inappropriate evidence can lead to a false assurance regarding the safe performance of a system. Having sufficient confidence in safety evidence is essential to avoid any unanticipated surprise during operational phase. Sometimes, however, it is impractical to wait for high quality evidence from a system’s operational life, where developers have no choice but to rely on evidence with some uncertainty (e.g., using a generic failure rate measure from a handbook to support a claim about the reliability of a component). Runtime monitoring can reveal insightful information, which can help to verify whether the preliminary confidence was over- or underestimated. In this paper, we propose a technique which uses runtime monitoring in a novel way to detect the divergence between the failure rates (which were used in the safety analyses) and the observed failure rates in the operational life. The technique utilises safety contracts to provide prescriptive data for what should be monitored, and what parts of the safety argument should be revisited to maintain system safety when a divergence is detected. We demonstrate the technique in the context of Automated Guided Vehicles (AGVs).

Series
Lecture Notes in Computer Science, ISSN 0302-9743 ; 10873
National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-38957 (URN)10.1007/978-3-319-92432-8_1 (DOI)2-s2.0-85049008966 (Scopus ID)9783319924311 (ISBN)
Conference
23rd International Conference on Reliable Software Technologies, Ada-Europe 2018, 18-22 June 2018, Lisbon, Portugal
Projects
SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication
Funder
EU, Horizon 2020, 692529 Vinnova
Available from: 2018-05-15 Created: 2018-05-15 Last updated: 2019-04-17Bibliographically approved
Joshi, S. L. L., Deshpande, B. & Punnekkat, S. (2017). An Industrial Survey on the Influence of Process and Product Attributes on Software Product Reliability. In: International Conference on Networks & Advances in Computational Technologies NetACT2017: . Paper presented at International Conference on Networks & Advances in Computational Technologies NetACT2017, 20 Jul 2017, Thiruvananthapuram, India (pp. 44-51). Thiruvananthapuram, India: IEEE
Open this publication in new window or tab >>An Industrial Survey on the Influence of Process and Product Attributes on Software Product Reliability
2017 (English)In: International Conference on Networks & Advances in Computational Technologies NetACT2017, Thiruvananthapuram, India: IEEE , 2017, p. 44-51Conference paper, Published paper (Refereed)
Abstract [en]

Software reliability is a major attribute for software product and can be considered as one of the major performance parameters. Software Reliability unlike hardware reliability cannot be considered merely as function of time, although researchers have come up with models relating the two. In literature, numerous models on software reliability have been proposed but they seem to have limitations in being used to predict reliability in software industry. As on today, we do not have good quantitative methods developed to represent Software Reliability without excessive limitations. Various approaches can be used to improve the reliability of software, however, it is hard to balance the development time and the budget with required levels of software reliability. This paper quantitatively and qualitatively analyzes the data from an industrial survey, with focus on current practices and their dependency on the estimation of reliability in software product development environment. Analysis focuses on perception of predicting software reliability in different categories of respondents. Categorization of respondent is based on phase of development, their profile (as user, developer etc.), and application domain. While confirming some commonly known facts, our findings also show discrepancies between our perception and actual facts in some cases. The objective of this is exercise is to find out input parameters making impact on reliability. Though it is field perception, we have identified them from practitioners and taken as reference for conducting future experiments and literature survey. We believe that continued research efforts are essential to provide guidelines for reliability estimation process to take care of important but hitherto ignored factors, thus improving relevance and accuracy of reliability predictions.

Place, publisher, year, edition, pages
Thiruvananthapuram, India: IEEE, 2017
Keywords
Software Reliability, Reliability prediction, Software products, Software Product Attributes
National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-37345 (URN)10.1109/NETACT.2017.8076739 (DOI)000426730100008 ()2-s2.0-85035318486 (Scopus ID)978-1-5090-6590-5 (ISBN)
Conference
International Conference on Networks & Advances in Computational Technologies NetACT2017, 20 Jul 2017, Thiruvananthapuram, India
Projects
Future factories in the CloudSafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication
Funder
EU, Horizon 2020, 692529 Vinnova
Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2019-04-18Bibliographically approved
Baumgart, S., Fröberg, J. & Punnekkat, S. (2017). Analyzing Hazards in System-of-Systems: Described in a Quarry Site Automation Context. In: 11th Annual IEEE International Systems conference SysCon: . Paper presented at 11th Annual IEEE International Systems conference SysCon17, 24 Apr 2017, Montreal, Quebec, Canada (pp. 544-551).
Open this publication in new window or tab >>Analyzing Hazards in System-of-Systems: Described in a Quarry Site Automation Context
2017 (English)In: 11th Annual IEEE International Systems conference SysCon, 2017, p. 544-551Conference paper, Published paper (Refereed)
Abstract [en]

Methods for analyzing hazards related to individual systems are well studied and established in industry today. When system-of-systems are set up to achieve new emergent behavior, hazards specifically caused by malfunctioning behavior of the complex interactions between the involved systems may not be revealed by just analyzing single system hazards. A structured process is required to reduce the complexity to enable identification of hazards when designing system-of-systems. In this paper we first present how hazards are identified and analyzed using hazard and risk assessment (HARA) methodology by the industry in the context of single systems. We describe systems-of-systems and provide a quarry site automation example from the construction equipment domain. We propose a new structured process for identifying potential hazards in systems-of-systems (HISoS), exemplified in the context of the provided example. Our approach helps to streamline the hazard analysis process in an efficient manner thus helping faster certification of system-of-systems.

Series
Annual IEEE Systems Conference
Keywords
Hazard Analysis and Risk Assessment, System-of-Systems, Autonomous Machines, Safety, Certification
National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-35503 (URN)10.1109/SYSCON.2017.7934783 (DOI)000403403400078 ()2-s2.0-85021435169 (Scopus ID)978-1-5090-4623-2 (ISBN)
Conference
11th Annual IEEE International Systems conference SysCon17, 24 Apr 2017, Montreal, Quebec, Canada
Projects
ITS-EASY Post Graduate School for Embedded Software and Systems
Available from: 2017-06-09 Created: 2017-06-09 Last updated: 2018-01-26Bibliographically approved
Mehmed, A., Punnekkat, S. & Steiner, W. (2017). Deterministic Ethernet: Addressing the Challenges of Asynchronous Sensing in Sensor Fusion Systems. In: 47th Annual IEEE/IFIP International Conference on Dependable Systems and Networks Workshops, DSN-W 2017; Denver; United States; 26 June 2017 through 29 June 2017: . Paper presented at The 47th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN 2017), 26-29 June 2017, Denver, Colorado, USA (pp. 22-28). , Article ID 8023693.
Open this publication in new window or tab >>Deterministic Ethernet: Addressing the Challenges of Asynchronous Sensing in Sensor Fusion Systems
2017 (English)In: 47th Annual IEEE/IFIP International Conference on Dependable Systems and Networks Workshops, DSN-W 2017; Denver; United States; 26 June 2017 through 29 June 2017, 2017, p. 22-28, article id 8023693Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we study the cause of out-of-sequence measurements (OOSM) and their effect on Kalman filter based multi-sensor fusion systems. We explore the current available solutions for handling of OOSM and pinpoint how the absence of precise measurement timestamps does not allow the correct chronological order of sensor measurements. The processing of such, out-of-order measurements, leads to negative-time measurement updates in the sensor fusion process, which in turn leads to a wrong representation of the environment.Furthermore, we present methods for achieving precise measurement timestamps. We explore the suitability of set of communication standards for improving the timestamp precision. In particular we focus on IEEE 802.1AS, IEEE 802.1Qav, Qbv and SAE AS6802 standards that enable deterministic communication over IEEE802.3 standard Ethernet. We present theoretical performance studies and comparison of the said communication standards.

National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-36084 (URN)10.1109/DSN-W.2017.44 (DOI)000425860600005 ()2-s2.0-85031711590 (Scopus ID)978-1-5386-2272-8 (ISBN)
Conference
The 47th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN 2017), 26-29 June 2017, Denver, Colorado, USA
Available from: 2017-07-10 Created: 2017-07-10 Last updated: 2018-03-15Bibliographically approved
Joshi, S. L. L., Deshpande, B. & Punnekkat, S. (2017). Do Software Reliability Prediction Models Meet Industrial Perceptions?. In: Proceedings of the 10th Innovations in Software Engineering Conference ISEC-2017: . Paper presented at Proceedings of the 10th Innovations in Software Engineering Conference ISEC-2017, 05 Feb 2017, Jaipur, India (pp. 66-73). ACM
Open this publication in new window or tab >>Do Software Reliability Prediction Models Meet Industrial Perceptions?
2017 (English)In: Proceedings of the 10th Innovations in Software Engineering Conference ISEC-2017, ACM , 2017, p. 66-73Conference paper, Published paper (Refereed)
Abstract [en]

Reliability is one of the key characteristics inherent in the concept "software quality". Understanding software reliability has been vital for both the software managers and software engineers, especially while developing critical systems. In the past several decades, an extensive body of knowledge has been developed and to a certain extent practical knowledge has been gathered by applying them to large scale mission- or safety-critical projects. However, software reliability models are falling short of gaining confidence in industrial community. From the software developer's perspective, software reliability has been primarily associated with defects, which represent a major cost factor in software development. This is called developer oriented approach. As software orientation has become ubiquitous, and software intensive systems have been proliferating, software quality assurance has been embracing more customer oriented perspectives. In this context, we will need richer, realistic and more accurate measures for software reliability. A recent empirical study by the authors highlighted many factors, which the practitioners perceived to be influential in the context of reliability prediction. This paper focuses on different reliability prediction models proposed in the literature, specifically examining whether the influential factors perceived to be contributing to the reliability are addressed or not in these models. We evaluated the assumptions made in each of the considered reliability models and checked their applicability in software product development. This paper concludes with a comparative presentation of a large set of well-known reliability models with respect to the set of factors identified by the industry as influential in software reliability.

Place, publisher, year, edition, pages
ACM, 2017
Keywords
Reliability, SDLC (Software Development Life Cycle), Software Product Attributes, Software products
National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-35445 (URN)10.1145/3021460.3021467 (DOI)978-1-4503-4856-0 (ISBN)
Conference
Proceedings of the 10th Innovations in Software Engineering Conference ISEC-2017, 05 Feb 2017, Jaipur, India
Available from: 2017-06-09 Created: 2017-06-09 Last updated: 2017-06-09Bibliographically approved
Gutiérrez, M., Steiner, W., Dobrin, R. & Punnekkat, S. (2017). Synchronization quality of IEEE 802.1AS in large-scale industrial automation networks.. In: Proceedings of the IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS: . Paper presented at 23rd IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS 2017, 18 April 2017 through 20 April 2017 (pp. 273-282). Institute of Electrical and Electronics Engineers Inc., Article ID 7939046.
Open this publication in new window or tab >>Synchronization quality of IEEE 802.1AS in large-scale industrial automation networks.
2017 (English)In: Proceedings of the IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS, Institute of Electrical and Electronics Engineers Inc. , 2017, p. 273-282, article id 7939046Conference paper, Published paper (Refereed)
Abstract [en]

Industry 4.0 and Industrial Internet of Things projects work towards adoption of standard IT technologies for real-time control networks in industrial automation. For this the IEEE 802.1 Time-Sensitive Networking (TSN) Task Group has developed and continues to develop a set of standards. One of these standards is the IEEE 802.1AS clock synchronization protocol. IEEE 802.1AS can be used to enable time-triggered communication as well as to coordinate distributed actions in industrial networks. In this paper we study the synchronization quality of IEEE 802.1AS and we are interested in whether the clocks can be synchronized with sufficiently low error such that the protocol can be used for demanding industrial automation applications. In particular, we study the protocol behavior in large-scale networks while considering critical implementation details. We report analytical worst-case results as well as probabilistic results based on simulations, that show that implementation details such as the PHY jitter and the clock granularity have a big impact on the time synchronization precision. 

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2017
National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-36142 (URN)10.1109/RTAS.2017.10 (DOI)000411195100031 ()2-s2.0-85021821793 (Scopus ID)9781509052691 (ISBN)
Conference
23rd IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS 2017, 18 April 2017 through 20 April 2017
Available from: 2017-07-27 Created: 2017-07-27 Last updated: 2017-10-27Bibliographically approved
Davis, R., Thekkilakattil, A., Gettings, O., Dobrin, R. & Punnekkat, S. (2016). Quantifying the Exact Sub-Optimality of Non-Preemptive Scheduling. In: Proceedings - Real-Time Systems Symposium: . Paper presented at 36th IEEE Real-Time Systems Symposium, RTSS 2015; San Antonio; United States; 1 December 2015 through 4 December 2015; Category numberE5651; Code 119070 (pp. 96-106). , jan
Open this publication in new window or tab >>Quantifying the Exact Sub-Optimality of Non-Preemptive Scheduling
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2016 (English)In: Proceedings - Real-Time Systems Symposium, 2016, Vol. jan, p. 96-106Conference paper, Published paper (Refereed)
Abstract [en]

Fixed priority scheduling is used in many real-time systems; however, both preemptive and non-preemptive variants (FP-P and FP-NP) are known to be sub-optimal when compared to an optimal uniprocessor scheduling algorithm such as preemptive Earliest Deadline First (EDF-P). In this paper, we investigate the sub-optimality of fixed priority non-preemptive scheduling. Specifically, we derive the exact processor speed-up factor required to guarantee the feasibility under FP-NP (i.e. schedulablability assuming an optimal priority assignment) of any task set that is feasible under EDF-P. As a consequence of this work, we also derive a lower bound on the sub-optimality of non-preemptive EDF (EDF-NP), which since it matches a recently published upper bound gives the exact sub-optimality for EDF-NP. It is known that neither preemptive, nor non-preemptive fixed priority scheduling dominates the other, i.e., there are task sets that are feasible on a processor of unit speed under FP-P that are not feasible under FP-NP and vice-versa. Hence comparing these two algorithms, there are non-trivial speedup factors in both directions. We derive the exact speed-up factor required to guarantee the FP-NP feasibility of any FP-P feasible task set. Further, we derive upper and lower bounds on the speed-up factor required to guarantee FP-P feasibility of any FP-NP feasible task set. Empirical evidence suggests that the lower bound may be tight, and hence equate to the exact speed-up factor in this case.

National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-29627 (URN)10.1109/RTSS.2015.17 (DOI)000380424600010 ()2-s2.0-84964677912 (Scopus ID)978-146739507-6 (ISBN)
Conference
36th IEEE Real-Time Systems Symposium, RTSS 2015; San Antonio; United States; 1 December 2015 through 4 December 2015; Category numberE5651; Code 119070
Projects
CONTESSE - Contract-Based Components for Embedded Software
Available from: 2015-12-10 Created: 2015-11-26 Last updated: 2016-08-18Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-5269-3900

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