1. A data management system for file and database management useful in concurrent engineering processes, comprising: a design control system for fulfilling requests of a user initiated from a computer system client system coupled to a network, including a data management control system for managing a plurality of projects, each project having a data repository for data records and a control repository comprising a common access interface and one or more databases selected from a group of databases which consists of one or more of: (a) a relational database having a collection of tables of data where the columns contain the attributes of related data and the rows are the instances of the data, and (b) an object oriented database having a collection of object instances of classes where the attributes are the members of the object class, and (c) a control file database having a collection of files where the records of the files are the instances of data and the attributes are arranged along the records, and (d) a directory database having a collection of file directories which may be or may not contain files whose relationships are described by the directory structure, and whose instances can be either sub-directories or files, said control repository communicating with users of said design control system for fulfilling requests of a user and the data repositories of said data management control system through a plurality of managers, each manager performing a unique function, wherein said managers act as building blocks which can be combined in a plurality of manners to support an environment for suitable for multiple users of a user community; and wherein said data management control system has a data management model structure capable of tracking a plurality of data objects governed under similar or disparate processes, wherein all objects are classified as part of a library, having one or more types, each type having one or more versions, and each version having one or more levels; and wherein said library is a grouping of objects which all have common characteristics causing them to belong to the same library grouping, and wherein within a library, data is organized by version, wherein versions allow parallel evolution of the same component data element to coexist in the same library enabling multiple versions of a component data element to be developed in tandem while using the same object name and residing in the same library and at the same level simultaneously; and for each said version, there is a level structure denoting a degree of completeness, stability or quality control enabling said data manager a means to establish a level structure commensurate with the goals and objectives of the user community, and wherein at least some of the data objects are at a level chained to another level to allow data to migrate from one Level to the next, and wherein any or all of these Levels can be designated as Entry Levels allowing data to be entered into this Entry Level from a user's Private Library; and wherein there are also levels categorized as working levels and release levels wherein data in working levels is transitory, and must eventually migrate to a release level, while release levels provide permanent storage vaults for a coherent set of data.