Phase II of the Track Database Auditing System (TDAS) program sought to produce a system development and implementation plan with a more comprehensive outline of the project approach and goals, as well as further refine the Concept of Operations (ConOps) and system requirements developed in the first phase. The refined system requirements were then further decomposed into subsystem requirement documents that established functions and capabilities for each subsystem, as well as Interface Control Documents (ICDs) to describe communication requirements between each subsystem, and between TDAS subsystems and other railroad subsystems. Finally, TTCI and the technical advisory group (TAG) generated and submitted a request for proposal (RFP) to vendors to establish candidates for development of testable prototypes for Phase III. TTCI evaluated responses to this RFP with the TAG, identifying a need for a modified approach to the prototype development and testing, and expansion of the pool of potential vendors.

See Also: 

Positive Train Control Track Data Auditing System
Positive Train Control Critical Asset Track Database Auditing System (TDAS): Phase II Appendices A Through M