For more than 25 years, the PMBOK Guide and its predecessors have been a leading tool for the project management profession and an essential reference for the library of every project manager. This edition continues the tradition of excellence in project management with a standard that is easy to understand and implement. The PMBOK Guide is recognized as the global standard for project management and is one of the best and most versatile resources available for the professional. It contains the fundamental practices that all project managers need to attain high standards for project excellence. This fourth edition has been updated to incorporate the most current knowledge and practices in project management. It focuses on improved consistency, clarity, and readability to facilitate understanding and implementation. Data flow diagrams for each process have been enhanced to show related processes for the inputs and outputs. The processes have been refined and reconfigured. The new edition also includes an appendix that addresses key interpersonal skills that a project manager utilizes when managing a project.