N-Tiered Test Automation Architecture for Agile Software Systems

Abstract

This paper introduces a multi-tiered test automation architecture to optimize test automation in an Agile software development environment while increasing both the test coverage and depth of each tier. Test Automation is the act of converting manual test cases into automated scripts that can be executed autonomously. In general, testing accounts for roughly 60% of the overall development budget and approximately 50% of that is attributed to regression testing. In recent years software organizations have begun migrating to Agile software development practices and automated testing in hopes of reducing the cost, lengthy regression cycles, and time to market. Traditionally, test automation is conducted on stable, non-changing applications. In an Agile environment where the code constantly changes, automated test cases become obsolete and must constantly be refactored in order to provide meaningful feedback about the system's quality. In most instances the cost of maintenance of automated test code completely overshadows the entire automation effort and negates any possible Return on Investment (RoI). An n-Tiered Test Automation Architecture seeks to retain the RoI by abstracting the automation project into separate distinct tiers; Presentation, Business, Data, and Services. These abstractions allow automated testing to continue providing feedback despite the constant revision of the system. A case study was conducted using this method and the observations showed that the automation architecture was resilient to change while increasing the test coverage, the depth of testing, and the overall quality of the application under test.