Showing papers by "Thomas J. Ostrand published in 2016"

Automated test generation using model checking: an industrial evaluation

Abstract: In software development, testers often focus on functional testing to validate implemented programs against their specifications. In safety-critical software development, testers are also required to show that tests exercise, or cover, the structure and logic of the implementation. To achieve different types of logic coverage, various program artifacts such as decisions and conditions are required to be exercised during testing. Use of model checking for structural test generation has been proposed by several researchers. The limited application to models used in practice and the state space explosion can, however, impact model checking and hence the process of deriving tests for logic coverage. Thus, there is a need to validate these approaches against relevant industrial systems such that more knowledge is built on how to efficiently use them in practice. In this paper, we present a tool-supported approach to handle software written in the Function Block Diagram language such that logic coverage criteria can be formalized and used by a model checker to automatically generate tests. To this end, we conducted a study based on industrial use-case scenarios from Bombardier Transportation AB, showing how our toolbox CompleteTest can be applied to generate tests in software systems used in the safety-critical domain. To evaluate the approach, we applied the toolbox to 157 programs and found that it is efficient in terms of time required to generate tests that satisfy logic coverage and scales well for most of the programs.

Experience Report: Automated System Level Regression Test Prioritization Using Multiple Factors

Abstract: We propose a new method of determining an effective ordering of regression test cases, and describe its implementation as an automated tool called SuiteBuilder developed by Westermo Research and Development AB. The tool generates an efficient order to run the cases in an existing test suite by using expected or observed test duration and combining priorities of multiple factors associated with test cases, including previous fault detection success, interval since last executed, and modifications to the code tested. The method and tool were developed to address problems in the traditional process of regression testing, such as lack of time to run a complete regression suite, failure to detect bugs in time, and tests that are repeatedly omitted. The tool has been integrated into the existing nightly test framework for Westermo software that runs on large-scale data communication systems. In experimental evaluation of the tool, we found significant improvement in regression testing results. The re-ordered test suites finish within the available time, the majority of fault-detecting test cases are located in the first third of the suite, no important test case is omitted, and the necessity for manual work on the suites is greatly reduced.

Transitioning Fault Prediction Models to a New Environment

Abstract: We describe the application and evaluation of fault prediction algorithms to a project developed by a Swedish company that transitioned from waterfall to agile development methods. The project used two different version control systems and a separate bug tracking system during its lifetime. The algorithms were originally designed for use on systems implemented with a traditional waterfall process at American companies that maintained their project records in an integrated database system that combined bug recording and version control. We compare the performance of the original prediction model on the American systems to the results obtained in the Swedish environment in both its pre-agile and agile stages. We also consider the impact of additional variables in the model.

Identifying fault-prone files in large industrial software systems

Abstract: We provide an overview of a decade-long research program aimed at identifying the most fault-prone files of large industrial software systems. We describe the motivation, approach used and results observed when we applied this technology to 170 releases of 9 different systems running continuously in the field. In all cases the files predicted to be most fault-prone accounted for most of the bugs in the system.