Effective unit-testing in model-based software development

Abstract

Model-based software development is extensively used in avionics and automotive safety critical control software applications. In model-based software development, highly optimized code is generated automatically from models. Such code is often hard to understand and this can make it difficult to write test cases. Therefore, in model based software development, test cases have to be derived based on the models to achieve coverage of code auto-generated from the models. Further, safety standards in those domains often demand effective unit-testing method to check functional requirements as well as achieve 100% code coverage.In this paper, we first discuss three methods for unit testing in model based software development, namely Modified Condition & Decision Coverage (MCDC), Classification tree and Exploratory methods. We then discuss results of our field study conducted on 3 live projects at Robert Bosch Engineering & Business Solutions Limited to check on the effectiveness of three approaches. Based on the results from our field study, we conclude that MCDC method along with boundary value analysis is most productive to check functional requirements as well as achieve 100% coverage of autogenerated code.

Effect of Model Based Software Development on Productivity of Enhancement Tasks -- An Industrial Study

“…Further, test design techniques have significant effect on productivity in model based software development. Our other work [17] showed that exploratory testing used in this study is least productive in model based software development. In our future work, we would also like to analyze the productivity of enhancement tasks using other test design techniques.…”

“…Unlike traditional software, enhancement tasks in model based development requires testing the model as well as the auto-generated code from the model to ensure required functionality is captured competently and auto-generated code is suitable to the target platform [17].…”

“…Various test design techniques exist to derive test cases. In this study, programmers used exploratory method [17] Additionally, the problems associated with model based software development [18] [19] like traceability of requirements to model and to generated code, understanding the highly optimized auto-generated code from model, copying differences between models, mapping defects identified in auto-generated code back to model, etc., may pose challenges on productivity of enhancement tasks in the model based software projects compared to traditional software projects.…”