According to the PMBOK Guide, a project management information system (PMIS) is an information system consisting of the tools and techniques used to gather, integrate, and disseminate the outputs of project management processes. It is used to support all aspects of the project from initiating through closing, and can include both manual and automated systems. A PMIS can help the project manager to create, collect, store, manage, control, and distribute project information, such as the project schedule, to relevant stakeholders.
Therefore, the project manager should have kept the documentation in the PMIS, and shared it with appropriate stakeholders, to ensure that the project schedule was updated and accessible. Updating the project management plan, assigning a project team member, or reviewing the risk register are not sufficient or relevant actions for handling the documentation for the project, as they do not address the issue of keeping the project schedule current and available. References: PMBOK Guide, Sixth Edition, pages 89-90, 558; PMI- PBA Guide, First Edition, pages 83-84, 87.