In project planning, maintaining documentation is necessary for which primary reason?

Maintaining documentation in project planning is essential primarily to ensure legal compliance. Documentation serves as a record of all agreements, decisions, changes, and communications that occur throughout a project. This is crucial in protecting all parties involved in case of disputes, misunderstandings, or legal claims. For instance, having clear documentation can demonstrate adherence to regulatory requirements, client expectations, and contractual obligations, thereby minimizing the risk of legal repercussions that can arise from project liabilities.

While the other options might also relate to project management objectives — such as managing costs, addressing subcontractor concerns, and improving profit margins — these are secondary benefits that may stem from good documentation practices. However, the foundational reason for maintaining thorough documentation is to fulfill legal requirements and provide a reliable record for accountability and dispute resolution, supporting the integrity and legality of the project as a whole.