The Validate step is ready for a new item (the last step’s Done column doesn’t count toward its WIP limit). However, the Implement step has no items that are done. The testers doing the Validate step are blocked. What should they do? Just as when the analyst was blocked, the best thing for the testers to do is to help with implementation (the prior step). They could implement some items, help with design or implementation issues, or work with partner teams to make implementation faster. They could even grab lunch for the development team—whatever is needed. If there’s no way for the testers to help with implementation, they can still be productive by analyzing bugs or usage patterns, running experiments, or improving tooling. There’s always productive work available that doesn’t hurt the team.