Experimental assessment of manual versus tool-based maintenance of GUI-directed test scripts

Since manual black-box testing of GUI-based APplications (GAPs) is tedious and laborious, test engineers create test scripts to automate the testing process. These test scripts interact with GAPs by performing actions on their GUI objects. As GAPs evolve, testers should fix their corresponding test scripts so that they can reuse them to test successive releases of GAPs. Currently, there are two main modes of maintaining test scripts: tool-based and manual. In practice, there is no consensus what approach testers should use to maintain test scripts. Test managers make their decisions ad hoc, based on their personal experience and perceived benefits of the tool-based approach versus the manual. In this paper we describe a case study with forty five professional programmers and test engineers to experimentally assess the tool-based approach for maintaining GUI-directed test scripts versus the manual approach. Based on the results of our case study and considering the high cost of the programmers' time and the lower cost of the time of test engineers, and considering that programmers often modify GAP objects in the process of developing software we recommend organizations to supply programmers with testing tools that enable them to fix test scripts faster so that these scripts can unit test software. The other side of our recommendation is that experienced test engineers are likely to be as productive with the manual approach as with the tool-based approach, and we consequently recommend that organizations do not need to provide each tester with an expensive tool license to fix test scripts.