Organization charts provide valuable if not essential data to organizations and companies of all types, particularly in reference to gathering a complete and thorough overview of the employees and participants in the organization or company, or the staff or employee grouping on a particular project or element and how they relate to one another within the organization. In terms of the project management world, the specific term organization chart refers to a particular tool that is used for the purposes depicting the complete and thorough interrelationships among the entire selection of individuals who are in the common role and unified position of working together to achieve and attain a common objective. The organization chart will typically depict all of the individuals and their titles, along with an indication of where each individual person ranks or sits in the leadership capacity for the purposes of determining who the decision makers of the group may be if a situation develops in which that person may need to be known.
This term is defined in the 3rd edition of the PMBOK but not in the 4th.