| 1. |
- Flemström, Daniel, 1971-
(författare)
-
Industrial System Level Test Automation
- 2021
-
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.
|
|
| 2. |
- Flemström, Daniel, et al.
(författare)
-
Industrial Scale Passive Testing with T-EARS
- 2021
-
Ingår i: Proceedings. ; , s. 351-361
-
Konferensbidrag (refereegranskat)abstract
- Passive testing continuously observes the system or system execution logs without any interference or instrumentation to test diverse combinations of functions, resulting in a more thorough evaluation over time. However, reaching a working solution to passive testing is not without challenges. While there have been some efforts to extract information from system requirements to create passive test cases, to our knowledge, no such efforts are mature enough to be applied in a real, industrial safety-critical context. Our passive testing approach uses the Timed - Easy Approach to Requirements Syntax (T-EARS) specification language and its accompanying tool-chain. This study reports challenges and solutions to introducing system-level passive testing for a vehicular safety-critical system through industrial data analysis, including 116 safety-related requirements. Our results show that passive testing using the T-EARS language and its tool-chain can be used for system-level testing in an industrial setting for 64% of the studied requirements. We identified several sources of false positive results and show how to tune test cases to reduce such false positives systematically. Finally, we show the requirement coverage achieved by a manual test session and that passive testing using T-EARS can find a set of injected faults that are considered hard to find with other test techniques.
|
|
| 3. |
- Flemström, Daniel, et al.
(författare)
-
Specification of Passive Test Cases Using an Improved T-EARS Language
- 2022
-
Ingår i: SOFTWARE QUALITY. - Cham : Springer Science and Business Media Deutschland GmbH. - 9783031041143 ; , s. 63-83
-
Konferensbidrag (refereegranskat)abstract
- Test cases that only observe the system under test can improve parallelism and detection of faults occurring due to unanticipated feature interactions. Traditionally, such passive test cases have been challenging to express, partly due to the use of complex mathematical notations. The T-EARS (Timed Easy Approach to Requirements Syntax) language prototype was introduced to respond to this and has received positive feedback from practitioners. However, the prototype suffered from few deficiencies, such as allowing non-intuitive combinations of expressions and usage of temporal specifiers that quickly got difficult to understand. This paper builds on the T-EARS prototype and input from experienced testers on a previous iteration of the language. The collected experience was applied to a new prototype using a structured update process, including a set of system-level requirements from a vehicular software system. The results include a new, improved grammar for the T-EARS language and a description of the evaluation semantics.
|
|
