First, we should assess under which project management reference umbrella we are speaking/working. The syntagm "Project Plan" is delicate and has numerous well-defined contents, according to a PM Methodology, BoK, Standard or Competence Baseline definitions.Usually, many project managers resume the Project Plan to a Schedule Plan assembled in MS Project or other SW tools for planning, and this represents the time baseline for the project management and control. Of course, it is not appropriate for a change request or, generally, for change control management.A comprehensive Project Management Plan (PMPl), including the Change Control Management should be assembled.Anyway, generally speaking for a serious and complex PMPl, it should be presented with the occasion of the 2-nd kickoff meeting when all the project stakeholders must meet, discuss, then iterate, and approve a such official document. If the change management is not presented, then the PMPl is not complete, and if officially approved it will remain a bad if not the worst plan with the respective gap. If not approved, one can not speak about a project managed on a planned basis and, of course, that is not a project defined in accordance to different worldwide definitions from Standards, PMMs, BoKs, etc.A possible future change request in the project without a comprehensive PMPl will not have any official basis for resolution, so the project might get temporarily stopped or further wrongly driven.The same is available for the project goal(s), objectives, and scope management. If they are not clearly defined in the PMPl, and appropriate plans are not included, then their accomplishment will be difficult to be monitored and controlled. If there are not established baselines, the project advances or progress can not be tracked and controlled, especially through EVM and ESM systems. Managing feelings usually comes under the umbrella of Stakeholder Engagement and Stakeholder Requirements Management, which is really difficult. Especially, speaking about this process for negative stakeholder management, no matter if they are internal or external (usually) ones.So, detailed project planning is a must for project success. This remains an iterative, rolling-wave and continuous enhancement process, actually a continuous quality improvement process.