The statement of work (SOW) would clarify what the project implementation partner was contractually expected to complete after disagreeing with the project manager about completed requirements. A SOW is a document that defines the scope, deliverables, schedule, and terms and conditions of a project or contract. A SOW typically includes information such as purpose, scope of work, location of work, period of performance, deliverables schedule, applicable standards, acceptance criteria, special requirements, and payment schedule.
A SOW can help to establish a common understanding and agreement between the client and the service provider on what needs to be done and how it will be done.

The project manager is using multiauthoring software to maintain the version control for the documentation of requirements. Multiauthoring software is a type of software that allows multiple users to create, edit, and collaborate on documents simultaneously. It also provides features such as tracking changes, commenting, reviewing, and merging versions. Multiauthoring software can help to improve the quality, accuracy, and consistency of documents and facilitate communication and feedback among stakeholders. Examples of multiauthoring software include Google Docs, Microsoft Word Online, and Confluence34

Update the project charter. Updating the project charter would be the next step for the project manager after identifying the project team during the project initiation phase. A project charter is a document that formally authorizes a project and defines its purpose, scope, objectives, deliverables, milestones, roles and responsibilities, assumptions, constraints, risks, budget, and timeline. A project charter can help to align the expectations and interests of all stakeholders involved in a project and provide direction and guidance for planning and executing the project.

The project manager should review the communication plan after learning about some communication issues with different stakeholders and team members. A communication plan is a document that defines and documents the communication goals, strategies, methods, channels, frequency, roles, and responsibilities for a project. A communication plan can help to facilitate effective and timely communication among all stakeholders involved in a project and avoid confusion, misunderstanding, or conflicts.