There was a time in industry when there were no such thing as a Project Manager, let alone the title. It actually became more and more recognized that there was a need for this specialization in the late 1980s. Prior to that time most companies simply put a team of Subject Matter Experts (SMEs) together to try to come up with a time line or due date for a new project or product to be developed and implemented.
Part of the problem that industry identified was that without some sort of scientific approach for the team to take, there were always delays and missed target dates. This had a definite impact on the ability to be competitive and beat your opponent to the market place with a new product or service.
Usually, the team leader was chosen by the department that needed the results of what the team was to produce. In the IT world, there were no "WINDOWS" applications let alone desk top PCs. This made tracking of a project very difficult, and also made it laborious to disseminate information amongst the various team members. This author was present in industry during these times and recognized the need for some sort of guide for project leaders to use so as to keep the project on track and make sure all of the team members were "on the same page" The results of this recognized need was the drafting of a document titled "Project Management Guidelines". It was published in the late 1980s by the company Ameritech, and became the guide for all future team leaders to use in their everyday work environment for Project Management.
Shortly thereafter, the rest of industry recognized the same need. It was noticed that Project Management principles were not just for the IT world, but could also be used multidisciplinary. It was then that the Project Management Institue came into being. This group recognized the need for the highly specialized discipline of Project Manager, and formed a "Certification" process whereby potential Project Managers could be trained in the same manner. Their guide for following the rules for this certification process was the development of the Project Management Book of Knowledge or more commonly known as the PMBOK.
Additionally, the Project Management Book of Knowledge has been adopted by many colleges and universities as the supplement to use when teaching Project Management courses, as well as other management classes. The Project Management Institute (PMI) has been recognized in industry as the leader in certifying the knowledge required to be an effective Project Manager. Not only do they conduct training classes and testing to demonstrate the learned knowledge, but they also host a wide array of seminars, groups, and networking opportunities for its members.
However, there are other certifications in existance for Project Managers that make the individual just as well qualified for the title, and this is the title of CPM, or Certified Project Manager, which is also one that is well disciplined in the art of project management techinques and practices.