In computer systems, it's relatively common to have a large problem which is broken up into multiple sub-problems, each of which is substantial in its own right and is in the realm of different subsets of students. Suppose there's two parts, A and B. Suppose that properly presenting B requires explanations and background which A establishes (concepts, principles, etc.), and preferably would reproduce some figures for clarity. However, A has been written but not yet accepted/published.
How should the authors of B proceed? Ideally the figures would be reproduced from the drafts and clearly cited as copies, but it seems weird as the original is yet unpublished. This also creates the worry that reviewers for a later submission of A would complain that these contributions are not novel as B's earlier publication have already presented them.