Because of their failure to do Configuration Management.
When a tank used in the war broke down and needed a replacement part, it will be ordered. Most of the replacement parts would arrive on time, but would not fit nicely, causing the tank to be put out of service. Over the next few months, the supply of the German tanks reduced considerably, and the Americans and Britishers triumphed.
Configuration Management is the solution to solve this wrong-replacement-part problem. It tracks the different revisions to the design, blueprints, technical specifications, and can tell you which one is the lastest revision, so that the right part can be identified.
Configuration Management is primarily a Version Control System for the Product of the Project.
Configuration management provides the documentation explaining why the project changes occurred, who approved the changes, and who the assigned change owner is. The PMBOK says that the Project Manager
is responsible for the following change management responsibilities:
1.Recognizing when a change has occurred.
2.Filtering out changes from inappropriate people.
3.Ensuring that change is beneficial.
4.Managing the changes as they occur.
Configuration management is the system for performing these responsibilities as well as
providing product, system and software version control.
