This is another aspect that we discovered over a period of time. At the start once we decided to follow scrum, we took each of the team, trained the team regarding scrum & team lead were trained to be a scrum master. Then one fine day we decided that everyone (dev & test) will follow scrum. A typical scrum team is self organizing. Team members pick up the task from the sprint backlog and burn them during the sprint. Each team works for the success of the sprint and adds a shippable increment to the component. And at the SOS (scrum of scrums) level all teams add a shippable increment to the product. This is the ideal situation that every one of us expected.
The reality was something different. At the end of the sprint we added an increment but it was not shippable. The bugs were found after the sprint delivery. The moment we had substantial number of bugs it cannot be called as a shippable increment. After some brainstorming we found the root cause. We took the conventional team setup and converted them to scrum teams. So we had development teams and testing teams. The development teams concentrated on adding new features. The testing teams took the last sprint delivery and tested the software. The target for the development team was to add more and more features. And the target for the testing team was to find all the bugs. Since the testing happened in the next sprint a sprint delivery became a shippable increment only after spending 2 sprints. We wanted to shorten this to a single sprint.
The solution we followed was to merge the testing and development teams together. Now a typical team contained a set of developers and testers. During the sprint the development and testing happened in parallel. Teams ensured that the bugs were resolved within the sprint. Those bugs which cannot be solved in the same sprint were scheduled in the following sprint. Now over a period of time the increment we added in a sprint became shippable increment. The lesson we learned was “development & testing goes hand in hand & scrum teams are cross functional”.