The PMBOK (Project Management Body of Knowledge) is a collection of knowledge and practices within project management. It is produced by the Project Management Institute and revised every 4 years. The PMBOK outlines 9 knowledge areas that define the processes, practices, inputs, outputs, tools, and techniques of project management. The 9 knowledge areas are: project integration management, project scope management, project time management, project cost management, project quality management, project human resource management, project communications management, project risk management, and project procurement management. Each knowledge area involves several core processes to achieve the objectives of that particular area.