First a bit of background :
Previously in V cycle process, we have a dev team and a product definition/tester team (we'll call them testers). We moved to agile few months ago with still this separation : people with dev knowledge and people for product definition/testing.
The dev team has for some time already continuous integration with automated non-regression testing. The tester team only has functional testing capacity, no dev possibility.
Also, the devs and the testers are in different location (video conference is used).
If helping for the solutions, we are using Jira for Scrum.
Current situation :
The devs and testers are in the same scrum team. Everyone is dedicated to the team for the duration of a sprint. User stories have acceptance criteria correctly set... So far so good.
However, the testing of the user stories is handled by the testers and not something like a test that check the acceptance criteria and allow or not the user story to be integrated (we add tests to check but they are not used for validation of the user story). And obviously, the testers cannot code as they don't have the knowledge to do so.
This leads us to an issue that when doing the sizing, we cannot make a sizing that make sense for both the devs and testers inside the same sprint. If we add up the sizing, when planning the sprint there is a high chance that one side with have 75% of the workload and the other almost nothing to do. And if we size for only one of the side, we ensure that one side will have the right amount for the sprint but the other side might not. We could size for both but then selection might not match priority is we want to have an adapted workload.
So far we sized the dev work and end up with a huge backlog of untested user stories (which can bite us if test are failing)
From what I read here and there, the solution is to have separated sprints and dev making validation based on the acceptance criteria (automated testing) and then the testers might do additional tests in their own sprint. However, the management wants that we keep everything in one sprint, one board...
So being unable to find a solution that would enable good sizing with both team working in the same sprint, I'm hoping some of you might have encountered the same issue and found a solution or have ideas about a possible improvement.
How to plan and manage sprints with user stories requiring a specific group to dev and a specific group to test for the user story acceptance without empty time for one group ?