A workforce management software has complex GUI (for example values in a page depends on the status (closed or open) of other pages). Only latest and near past development has test coverage. During our last release, we received lots of bugs from customer in-spite of 2 weeks of testing Sprint. We don't have dedicated test team. The developers does the unit test and User acceptance test. Every day triggers automated regression test.I am afraid the developers are not testing the entire workflow because its time consuming also not able to automate it because of its complexity. Any suggestions? The legacy code (15 years of development) has less code coverage. How can I improve quality?Note: Now not possible to hire testers to have independent test team.
Facing quality issues
agile;testing;quality;maintenance
It sounds like the complexity of the legacy system is such that none of the developers really understand yet all the dependencies and coupling.  In being assigned user stories they are modifying code that is causing bugs in other areas and functionality because of this unfamiliarity.This is a problem that in the short term can only be solved by setting aside additional hours for user acceptance testing for every user story.  Without a dedicated tester this will significantly slow down development time.In the long term however, refactoring and lowering coupling along with gradual incorporation of unit tests will help the software become more stable.You have stated several times already that hiring a dedicated tester is not possible, but it is important.  Try to convince management that it is a good idea.  Testers cost less money than developers, so if a developer is performing the user acceptance testing then you can argue that the manager is paying too much money for testing work per hour.  If you think about it, hiring a tester will save the boss money.