| 1. |
- Brahneborg, Daniel, 1970-, et al.
(författare)
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Round-Trip Time Anomaly Detection
- 2018
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Ingår i: ICPE '18 Proceedings of the 2018 ACM/SPEC International Conference on Performance Engineering. - New York, NY, USA : ACM. - 9781450350952 ; , s. 107-114
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Konferensbidrag (refereegranskat)abstract
- Mobile text messages (SMS) are sometimes used for authentication, which requires short and reliable delivery times. The observed round-trip times when sending an SMS message provide valuable information on the quality of the connection. In this industry paper, we propose a method for detecting round-trip time anomalies, where the exact distribution is unknown, the variance is several orders of magnitude, and there are lots of shorter spikes that should be ignored. In particular, we show that using an adaption of Double Seasonal Exponential Smoothing to reduce the content dependent variations, followed by the Remedian to find short-term and long-term medians, successfully identifies larger groups of outliers. As training data for our method we use log files from a live SMS gateway. In order to verify the effectiveness of our approach, we utilize simulated data. Our contributions are a description on how to isolate content dependent variations, and the sequence of steps to find significant anomalies in big data.
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| 2. |
- Flemström, Daniel, et al.
(författare)
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A Research Roadmap for Test Design in Automated Integration Testing of Vehicular Systems
- 2016. - 9
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Ingår i: FASSI 2016. - : International Academy, Research and Industry Association (IARIA). - 9781612084978 ; , s. 18-23
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Konferensbidrag (refereegranskat)abstract
- An increasing share of the innovations emerging in the vehicular industry are implemented in software. Consequently, vehicular electrical systems are becoming more and more complex with an increasing number of functions, computational nodes and complex sensors, e.g., cameras and radars. The introduction of autonomous functional components, such as advanced driver assistance systems, highlight the foreseeable complexity of different parts of the system interacting with each other and with the human driver. It is of utmost importance that the testing effort can scale with this increasing complexity. In this paper, we review the challenges that we are facing in integration testing of complex embedded vehicular systems. Further, based on these challenges we outline a set of research directions for semi-automated or automated test design and execution in integration testing of vehicular systems. While the discussion is exemplified with our hands-on experience of the automotive industry, much of the concepts can be generalised to a broader setting of complex embedded systems.
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| 3. |
- Flemström, Daniel, et al.
(författare)
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Exploring Test Overlap in System Integration : An Industrial Case Study
- 2016
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Ingår i: 42nd Euromicro Conference series on Software Engineering and Advanced Applications SEAA 2016. - 9781509028191 ; , s. 303-312
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Konferensbidrag (refereegranskat)abstract
- Tougher safety regulations, global competition and ever increasing complexity of embedded software puts extensive pressure on the effectiveness of the software testing procedures. Previous studies have found that there exist overlaps (i.e., multiple instances of highly similar test cases) and even redundancies in the software testing process. Such overlap has been found between versions, variants and integration levels, but primarily at unit test level. Given large embedded systems involving many subsystems, does overlap exist within the system integration testing as well? In this paper, we present an industrial case study, aiming to a) evaluate if there exist test overlaps within the given context, b) if so, investigate how these overlaps are distributed, and c) find ways of reducing test effort by investigating how the knowledge of overlaps and their distribution may be used for finding candidate test cases for automation, maintenance or even removal. We have studied manual test cases, written in natural language, at a large vehicular manufacturer in Sweden. In particular, we have collected and analyzed test cases from the system integration testing levels of four different projects of a vehicle control management system. Using a similarity function, we evaluate if any overlaps between test cases exist, and where. We found that overlaps do exist within the system integration level, particularly in the form of partial test step sequences. However, very few test cases overlapped in their entirety. Some candidates for test step automation and update propagation were identified, but none for easy removal.
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| 4. |
- Flemström, Daniel, et al.
(författare)
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From natural language requirements to passive test cases using guarded assertions
- 2018
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Ingår i: Proceedings - 2018 IEEE 18th International Conference on Software Quality, Reliability, and Security, QRS 2018. - : Institute of Electrical and Electronics Engineers Inc.. - 9781538677575 ; , s. 470-481
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Konferensbidrag (refereegranskat)abstract
- In large-scale embedded system development, requirements are often expressed in natural language. Translating these requirements to executable test cases, while keeping the test cases and requirements aligned, is a challenging task. While such a transformation typically requires extensive domain knowledge, we show that a systematic process in combination with passive testing would facilitate the translation as well as linking the requirements to tests. Passive testing approaches observe the behavior of the system and test their correctness without interfering with the normal behavior. We use a specific approach to passive testing: guarded assertions (G/A). This paper presents a method for transforming system requirements expressed in natural language into G/As. We further present a proof of concept evaluation, performed at Bombardier Transportation Sweden AB, in which we show how the process would be used, together with practical advice of the reasoning behind the translation steps.
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| 5. |
- Flemström, Daniel, 1971-
(författare)
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Industrial System Level Test Automation
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Vehicular software systems control and monitor many safety-critical functions, such as automated emergency brakes and anti-spin. These functions are integrated and tested at system level to ensure that the entire system works as intended.Traditionally, these functions or selected combinations of functions are tested in isolation. Although desired, rigorous testing of combinations of functions prior to deployment is seldom possible. One reason is the overwhelming work required to write new test cases for the nearly infinite combinations of functions and driving scenarios. Since software testing already accounts for up to 60% of the software development cost and the execution time in test rigs is expensive, further testing must be achieved by running test cases more in parallel. Moreover, new test cases must be reusable in different driving scenarios to cover more combinations of functions. One solution is to express the test logic in a new way so that it can be executed in parallel, independently of other tests and independent of the input stimuli. This would allow reusing the test logic for different sequences or drive scenarios. Passive testing is one such approach that has not yet been used much for vehicular software due to perceived difficulties, although it is well-established in other domains. One particular problem is how to specify and execute passive test cases for vehicular systems in an, for the test engineer, intuitive and straightforward manner. Further, there is a lack of tool support and knowledge on efficiently applying passive testing in an industrial context. Thus, the overall research goal of this thesis is to propose and evaluate industrially applicable methods and tools for passive testing at the system level of vehicular software systems. The research is based on a series of papers and case studies within the vehicular industry. In contrast to existing specification languages based on formal mathematical expressions, considerable effort was spent creating an intuitive language and an interactive tool, simple but powerful enough, to encourage the industrial application of passive testing. The main contributions include an easy-to-write and easy-to-read description language for passive test cases, an interactive development environment, and knowledge on how to succeed in passive testing in an industrial software development process. The findings of this thesis contribute to making passive testing a viable method for system-level testing and a way of reusing test logic. In the case of a studied train control management system, using passive testing may reuse up to 50% of the test logic for the safety-related requirements and 10% of the non-safety-related requirements.
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| 6. |
- Flemström, Daniel, et al.
(författare)
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Similarity-based prioritization of test case automation
- 2018
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Ingår i: Software quality journal. - : Springer Science and Business Media LLC. - 0963-9314 .- 1573-1367. ; 26:4, s. 1421-1449
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Tidskriftsartikel (refereegranskat)abstract
- The importance of efficient software testing procedures is driven by an ever increasing system complexity as well as global competition. In the particular case of manual test cases at the system integration level, where thousands of test cases may be executed before release, time must be well spent in order to test the system as completely and as efficiently as possible. Automating a subset of the manual test cases, i.e, translating the manual instructions to automatically executable code, is one way of decreasing the test effort. It is further common that test cases exhibit similarities, which can be exploited through reuse when automating a test suite. In this paper, we investigate the potential for reducing test effort by ordering the test cases before such automation, given that we can reuse already automated parts of test cases. In our analysis, we investigate several approaches for prioritization in a case study at a large Swedish vehicular manufacturer. The study analyzes the effects with respect to test effort, on four projects with a total of 3919 integration test cases constituting 35,180 test steps, written in natural language. The results show that for the four projects considered, the difference in expected manual effort between the best and the worst order found is on average 12 percentage points. The results also show that our proposed prioritization method is nearly as good as more resource demanding meta-heuristic approaches at a fraction of the computational time. Based on our results, we conclude that the order of automation is important when the set of test cases contain similar steps (instructions) that cannot be removed, but are possible to reuse. More precisely, the order is important with respect to how quickly the manual test execution effort decreases for a set of test cases that are being automated.
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| 7. |
- Flemström, Daniel, 1971-
(författare)
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Similarity-Based Test Effort Reduction
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Embedded computer systems are all around us. We find them in everything, from dishwashers to cars and airplanes. They must always work correctly and moreover, often within certain time constraints. The software of such a system can be very large and complex, e.g. in the case of a car or a train. Hence, we develop the software for embedded systems in smaller, manageable, parts. These parts can be successively integrated, until they form the complete software for the embedded system, possibly at different levels. This phase of the development process is called the system integration phase and is one of the most critical phases in the development of embedded systems. In this phase, substantial effort is spent on testing activities.Studies have found that a considerable amount of test effort is wasteful due to people, unknowingly or by necessity, performing similar (or even overlapping) test activities. Consequently, test cases may end up to be similar, partially or wholly. We identified such test similarities in a case study of 2500 test cases, written in natural language, from four different projects in the embedded vehicular domain. Such information can be used for reducing effort when maintaining or automating similar test cases.In another case study in the same domain, we investigated several approaches for prioritizing test cases to automate with the objective to reduce manual test effort as quick as possible given that similar automated tests could be reused (similarity-based reuse). We analyzed how the automation order affects the test effort for four projects with a total of 3919 integration test cases, written in natural language. The results showed that similarity-based reuse of automated test case script code, and the best-performing automation order can reduce the expected manual test effort with 20 percentage points.Another way of reducing test effort is to reuse test artifacts from one level of integration to another, instead of duplicating them. We studied such reuse methods, that we denote vertical reuse, in a systematic mapping study. While the results from of our systematic mapping study showed the viability of vertical test reuse methods, our industrial case studies showed that keeping track of similarities and test overlaps is both possible and feasible for test effort reduction. We further conclude that the test case automation order affects the manual test execution effort when there exist similar steps that cannot be removed, but are possible to reuse with respect to test script code.
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| 8. |
- Flemström, Daniel, et al.
(författare)
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Vertical Test Reuse for Embedded Systems : A Systematic Mapping Study
- 2015. - 11
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Ingår i: 2015 41st Euromicro Conference on Software Engineering and Advanced Applications. - : Conference Publishing Services. - 9781467375856 ; , s. 317-324
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Konferensbidrag (refereegranskat)abstract
- Vertical test reuse refers to the the reuse of test cases or other test artifacts over different integration levels in the software or system engineering process. Vertical test reuse has previously been proposed for reducing test effort and improving test effectiveness, particularly for embedded system development. The goal of this study is to provide an overview of the state of the art in the field of vertical test reuse for embedded system development. For this purpose, a systematic mapping study has been performed, identifying 11 papers on vertical test reuse for embedded systems. The primary result from the mapping is a classification of published work on vertical test reuse in the embedded system domain, covering motivations for reuse, reuse techniques, test levels and reusable test artifacts considered, and to what extent the effects of reuse have been evaluated.
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| 9. |
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| 10. |
- Abbas, Muhammad, et al.
(författare)
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Automated Reuse Recommendation of Product Line Assets Based on Natural Language Requirements
- 2020
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Ingår i: Lecture Notes in Computer Science. - Cham : Springer Science and Business Media Deutschland GmbH. - 9783030646936 ; , s. 173-189, s. 173-189, s. 173-189
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Konferensbidrag (refereegranskat)abstract
- Software product lines (SPLs) are based on reuse rationale to aid quick and quality delivery of complex products at scale. Deriving a new product from a product line requires reuse analysis to avoid redundancy and support a high degree of assets reuse. In this paper, we propose and evaluate automated support for recommending SPL assets that can be reused to realize new customer requirements. Using the existing customer requirements as input, the approach applies natural language processing and clustering to generate reuse recommendations for unseen customer requirements in new projects. The approach is evaluated both quantitatively and qualitatively in the railway industry. Results show that our approach can recommend reuse with 74% accuracy and 57.4% exact match. The evaluation further indicates that the recommendations are relevant to engineers and can support the product derivation and feasibility analysis phase of the projects. The results encourage further study on automated reuse analysis on other levels of abstractions.
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