User story not completed in successive sprints

The Developers should ask themselves if it was sufficiently refined and Ready for Sprint Planning, and to be aware that regardless of whether or not it is completed, their Sprint Goal commitment must be achieved.

Is the team discussing this problem at their Sprint Retrospective? That would be a good opportunity to understand the impact of not completing the work on the Sprint Goal, understand why the work is taking a long time to complete, and find ways to ensure that work is refined and decomposed sufficiently to be completed within a Sprint.

Great advice has been given. 

Some questions that come to mind…

Has this PBI (product backlog item) been required to achieve the outcome of the Sprint Goal in each of these Sprints? If not, perhaps it wasn’t a priority to complete, with work needed to achieve Sprint Goal taking priority.

If it was needed to achieve the Sprint Goal, in both Sprints, what has been made transparent about this PBI? Is there a dependency? Is the scope of the PBI too big, requiring an adjustment of scope or perhaps breaking it down into smaller valuable slices? What has been discussed at retrospective? What planning has occurred at Sprint Planing to discuss how to address this item? Has this PBI come up during Daily Scrums as Developers make their plan for the day to make progress on the Sprint Goal? If this item impedes progress towards achieving the Sprint Goal, what has been done to move it forward?