Fehlerhäufigkeiten in objektorientierten Systemen: Basisauswertung einer Online-Umfrage

Für einen effizienten Einsatz von Qualitätssicherungsmaßnahmen ist die Kenntnis über die häufigsten Fehlerursachen entscheidend. Dieser Artikel beschreibt die Ergebnisse einer Online‐Umfrage zu Fehlerhäufigkeiten in objektorientierten Systemen. Die Umfrage wurde vom Arbeitskreis „Testen objektorientierter Programme“ der GI(Gesellschaft für Informatik) mit 1219 Teilnehmern im Zeitraum vom 19. August bis 31.Oktober 2005 durchgeführt

Testability Measurement and Software Dependencies

Testability is an important quality characteristic of software. A lack of testability contributes to a higher test and maintenance effort. Metrics can be used locate parts of a program which contribute to a lack of testability. In this paper we present a new approach to define metrics for software dependencies. We use this approach in the context of testability to identify test-critical dependencies, i.e. those dependencies within a system that are critical for test complexity. The results of four case studies show that 1) a small subset of the dependencies within a system has an exceedingly high impact on particular testability metrics, 2) conventional coupling metrics are not good predictors of these test-critical dependencies, 3) dependencies automatically identified to be test-critical are good indicators of design that needs improvement

Design for Testability

Testability is a software quality characteristic that is of major relevance for test costs and software dependability. Still, testability is not an explicit focus in today’s industrial software development projects. Related processes, guidelines, and tools are missing. This paper is about design for testability, the main intersection of software design and testing. We describe 1) elements of object-oriented software design that may cause testing problems and 2) guidelines on how to improve testability including the use of design patterns. The special focus is on system dependencies and observability

Another Motivation for Usage Models: Generation of User Documentation

The reliability of a software product depends on the number of residual faults as well as on its usage. Trustable reliability testing techniques therefore rely on a formal usage model that allows to test software under conditions similar to its intended usage. The effort to define a usage model is significant, but it pays off not only in terms of reliability prediction but also by supporting system design and test planning. This work investigates the possibility of utilizing usage models in another way, namely to automatically generate user documentation. A prototype tool has been implemented, based on an extended usage model formalism. The evaluation of the prototype based on a sample application shows that this approach is both feasible and promising