The Project Management Book of Knowledge (PMBOK) defines a Project Management Information System (PMIS) as 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.
Plan, track, and analyze project schedule including critical path
Manage resources effectively including resource leveling, loading, allocation, etc.
Organize and analyze data into meaningful graphical reports like tables or charts that can be shared easily among stakeholders
Analyze and control cost and performance, updating existing plans as actual against planned data changes. Allow project manager to evaluate different scenarios with their effects