This Part 3 of the standard specifies the requirements for the overall functionality and engineering services to achieve building automation and control systems. It defines terms, which shall be used for specifications and it gives guidelines for the functional documentation of project/application specific systems. It provides a sample template for documentation of plant/application specific functions, called BACS points list in annex A. The informative function block examples explain a method to display the referenced functions in system documentation; they do not standardize the method for programming functions and applications. This part of the standard covers the following: Requirements and definitions regarding BACS and application software, generic functions for plant/project specific applications and engineering functions for building controls and operations. It provides communication functions for the integration of other dedicated special system processes. The functional requirements in this part of the standard are subdivided as follows: - System management and application software: describes the requirements for plant independent systems and human system interface programs related to a project, including the operating system. This standard does not dedicate the following system functionality to any particular hardware, e.g.: - system diagnostics, watchdog, redundancy, time keeping, access control, log lists; - point identification, event message handling, print control; - database, statistics, data archiving, remote access; - system communicatins...........