Click for next page ( 26


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 25
25 Table 5. TEAP peer review panel. Streamlined EA Process--Streamlined approach for col- lecting information to customize the reference architecture List of Participating Organizations in the Reference TEAP Peer Review Panel to meet a transit agency's enterprise Cape Cod Regional Transit Authority C-Tran These topics are overviewed in the sections that follow. The Dallas Area Rapid Transit (DART) wiki contains the details and in-depth descriptions of the mod- EA Works els, tools, and process. FTA Headquarters King County Metro Miami-Dade County TEAP Metamodel Overview New Jersey Transit New York City Transit As discussed in the beginning of this chapter, an important PACE aspect of the reference architecture, or any EA in general, is EA Expert (retired) the entities that compose the EA and their relationship to TriMet Utah Transit Authority each other. The TEAP metamodel (see Figure 5) is a very close VIA--San Antonio replica of WMATA's EA metamodel; it shows the institu- WMATA tional and technical architecture drivers in the vertical box (on the left), and then the four typical enterprise architecture layers (business, information, applications, and technology) payment system, and the emerging mobile/branded card pay- in the horizontal boxes on the right side of the diagram. Some ment system. entities are fully contained within other entities; for example, In the final workshop, the discussion centered around how a business domain includes several business functions which to represent different fare management configurations, and specializes the functions into business processes. The links how to generically represent applications and technology com- between the Information View and Business Process, or Infor- ponents. The results of these discussions and the workshop mation View and Measure indicate that there is a connection recommendations were posted on a private wiki site for which (perhaps dependency) between the paired entities. The meta- all participants had writer-level access. Several transit agen- model is the foundation of the enterprise and does not readily cies reviewed the resulting artifacts; some agencies applied change. Perhaps the most important aspect of the metamodel their existing systems to the model or solutions to validate is to describe the general relationships between entities. The them. The results of these pilots are described in Chapter 6. reference architecture can then use this model to describe The final reference architecture, the four fare management entities and their specific relationship to each other. For exam- solutions, streamlined implementation guidance (with tools ple, an Information View element called ridership may be linked and templates), and approach for incorporating solutions were to a Measure called monthly ridership statistics. included in the Phase I wiki site. An Access database and Excel spreadsheets were developed that represent the entities and relationships described by the metamodel diagram. Transit agencies may use these as tem- What Is in the Reference Enterprise plates to collect information about their organization. Architecture for Transit? The reference architecture is composed of several sets of Overview of the Reference entities, including the following: Enterprise Architecture for Transit Metamodel--Model that shows the organization of the The Reference Enterprise Architecture for Transit is the con- Reference Enterprise Architecture for Transit tent that is inserted into the TEAP metamodel. Based on the Reference Enterprise Architecture for Transit--Model that metamodel, the reference model is divided into several sections: shows the reference architecture, including all the entities and relationships Architecture Drivers including Diagram of the model Vision/Mission Templates and tools that explicitly define the four EA Transitional Processes layers, and the institutional and technical drivers of a Locations Transit Enterprise Architecture Standards Fare Management Solutions--Four different configurations/ Business including solutions for implementing the fare management segment Business Domain of the Reference Enterprise Architecture for Transit Organization

OCR for page 25
26 Figure 5. TEAP metamodel. (Source: Adapted from WMATA Enterprise Architecture, June 2009. Licensed under a Creative Commons Attribution-ShareAlike License [CC BY-SA].) Information Architecture Driver Layer Overview Applications (and related databases) and Application The architecture drivers are composed of four major areas Families including mission, transitional processes, locations, and Technologies related to their ITS System/Center association standards. or Communication Mission. The mission topic describes the mission, vision, Each of these layers includes a model that depicts the enti- goals, and related objectives. The vision/mission drives the ties and relationships and a table with descriptions for each of corporate goals, and for each goal there are one or more mea- the entities. The descriptions are contained in a spreadsheet surable objectives. Performance measures may be categorized and database. The database describes the relationships between by different classification schemes. For example, organizations entities (within a layer or between layers). may classify their (performance) measures based on safety,

OCR for page 25
27 customer service, and productivity. Each measure is related Business Layer Overview to one or more objectives (and vice versa; each objective may be related to one or more measures). A typical performance The business layer includes the business processes and measure may be "monthly ridership statistics." A corporate organizational structure. These entities are inextricably linked. goal is to increase ridership while the objective may state: Business Process. Business process entities are composed increase ridership on new routes by 2 percent per quarter of the business domain, functions, and processes. Each business over the next 2 years. domain, function, and process is described from a high level. Transitional Processes. The transitional processes entity The TEAP uses WMATA's approach for classifying the enter- lists the programs and specific IT projects planned or active prise. There are three domains: administration functions, that effect change to the architecture. This category may also operations and service level functions, and then cross-cutting, be seen as a "Project Portfolio" or it may describe areas related executive, and interagency (e.g., security, safety, and customer to an IT strategic plan. This is the link that connects the TEAP service) functions. The reference architecture summarizes the to the TEAP Framework elements (i.e., business case, fund- enterprise to the business process level; however, many agencies ing, systems engineering, and PIR). Additionally, the project create flow charts that describe business processes to more and/or program models connect to almost every entity. The detailed levels, down to specific operating procedures, sub- transitional processes help keep track of "to-be" elements in processes, decision points, and events (triggers). the architecture. As mentioned above, the Reference TEAP includes three major Business Domains: Locations. The locations entity is a means of assigning a "location" to the physical technologies and assets. It is also Enterprise Administration Domain--Supports back-office a means of categorizing these things using the National ITS and other administrative functions Architecture centers and system nomenclature by categoriz- Integration Domain--Supports cross-cutting, executive, ing it by a type--mobile/vehicle, field, center or traveler. The and customer functions information contained in a locations table may include the Transit Management Domain--Supports operations, main- following: tenance, and support related to providing the service to the customer ITS Type (Mobile/Vehicle, Field, Center, Traveler) Grouping (e.g., Facilities, General, Mobile, Offices, Stations) Organizational Structure. The organizational structure Location Name is composed of directorates, directorates are composed of Description departments, and departments are composed of offices. If the Address levels of an organization need more than three levels, then Telephone offices may be composed of one or more offices. Latitude Longitude Information Layer Overview A locations table entry is associated with each technology The information layer is composed not of specific data- entry. For example, a server is located in a facility such as the bases and data sets, but of the "data dictionary" clustered agency headquarters and the backup server may be located in into critical data sets. The information layer includes the a data center located at an offsite facility. information domain, subject area, and information views in a hierarchical relationship. Many information domain enti- Standards. The standards entity is composed of IT and ties correspond to business functions with the same name, ITS standards; IT policies (such as branding, privacy, security); such as: and other regional agreements that drive business processes, information, applications, or technology. Any regional agree- Enterprise Asset Management ments that share networks may include a Level of Service agree- Human Capital Management ment. The network would be linked to the Level of Service Financial Management agreement. Applications that implement a Transit Communi- Operations Management and Supply Chain cations Interface Profile (TCIP) standard dialog would link to Safety the Profile Information Conformance Specification (PICS). Enterprise Management Each of the three entities contained in the Standards entity may Customer Service link to Information, Application, or Technology entities. Security