The IRS mission and strategic goals are implemented through a five-year plan that drives information technology investment decisions based on priorities around modernizing front-line tax administration and supporting technical infrastructure. EA leverages existing systems, as defined in the As-Built Architecture, and new development to build capabilities, optimize capacity, manage program costs, and deliver business value on an incremental and frequent basis. This business vision and strategy is then documented within the EA’s Enterprise Transition Plan.

To achieve this objective, segment architecture is used to identify the enterprise segments and to link enterprise-level planning with the development and implementation of solution architecture. Segment architecture is fully reconciled with the agency enterprise architecture. Business investments and resources are also fully aligned with the approved segment architecture. Segment architecture is developed to support a clear and concise value proposition linked to the agency mission, as well as to its strategic goals and objectives.

The vision and strategy framework is built on the functional segmentation of the IRS, representing the core mission business functions that directly relate to front-line tax administration. These segments, or business domains, reflect a purely functional rather than organizational view of the business, and ensure that business priorities remain the focus of IRS IT investments.

The IRS Business Domains include:

The IRS Service Domains include:

The Technical Services Domains include:

The core IRS business processes support the strategic goals as described in the Strategic Plan. The matrix is provided to assist in business case development and provide stronger justifications of proposed improvements to IRS business processes by demonstrating a clearer line of sight to IRS business results.

The IRS EA presents programmatic requirements for the IRS Business Systems Modernization Program. These programmatic requirements have been mandated by higher authorities and exist independently of EA. Given the broad scope of many of the referenced requirements, some provisions of some of these requirements may not be fully applicable to the IRS business systems modernization program. EA describes programmatic requirements as those based on security and privacy; the IRS; and all agencies.

The Security Requirements model specifies security requirements for the IRS Enterprise Target Architecture (ETA). In addition to that model, EA specifies security requirements for traceability of Privacy and Technical Security Requirements to Business Process Security and Privacy Considerations and the crosswalk of NIST SP 800-53 and ETA Security Requirements.

The security architecture view of the Target Architecture consists of other models besides the three named just above. Other models of the security view include:

Privacy Requirements Models: The primary purpose of the Privacy Requirements model is to specify privacy requirements for the IRS Enterprise Target Architecture (ETA). In addition to that model, a supporting model is also included highlighting the traceability of Privacy and Technical Security Requirements to Business Process Security and Privacy Considerations: tracing privacy requirements models to privacy considerations of target business processes.

Other Models of the Target Architecture Privacy View: The privacy architecture view of the Target Architecture consists of other models besides the two named just above. Other models of the privacy view include:

The IRS EA describes high-level system performance requirements. Five categories of performance requirements are specified, including Enterprise Workload, Enterprise Response Time, Enterprise Reliability, Maintainability, and Availability Requirements. These performance requirements are primarily based on the performance goals specified in the Process Thread Performance Matrix (provided in the EA’s Performance Architecture section). However in many cases, the performance goals specified by these matrices are incomplete. Therefore, they have been supplemented by information from sources such as the tax statistics area of http://www.irs.gov. Future versions of the Business Architecture are expected to provide more complete specification of performance goals. This will lead to expansion and refinement of the performance requirements specified herein, and may result in replacement of some of the requirements based on supplemental sources.

The Enterprise Systems Management (ESM) Requirements exist primarily because systems and networks are not currently self-healing. In order to move the IRS towards the goal of self-healing, self-managed systems, applications, and networks, all devices, systems, applications, processes, and system platforms must participate in the overall systems management strategy. All ESM functions must be closely integrated with each other, provide for extensibility, scalability, and secure operation, and afford extensive multi-platform management capability.

Arrays of management capabilities must be provided in order to achieve a "best-practice" ESM solution for the IRS. The ESM solution deployed at the IRS must be flexible enough to adapt to a wide variety of operational models. Producing an Enterprise-wide solution provides for a high degree of flexibility with regard to implementing evolutionary changes to the operational model with the least amount of disruption to service levels.

The EA describes the Enterprise-level, future-state functional requirements that will support the modernized IRS. The Business Process Model includes:

A Business Service is a complete business transaction or interaction that the IRS conducts with a customer, partner, or stakeholder. It can be a tax service or a service that provides a tax product. Like other business enterprises, the IRS offers an array of services, similar to a menu or catalog of services that identifies the various products and services that one can obtain from that business enterprise.

The EA describes the future-state business processes that will support the IRS. The Business Process Model includes:

The EA provides business scenarios that demonstrate how selected business processes contained in the EA support key business events. These scenarios were developed in response to requests from the business community to meet two objectives:

The IRS has added custodial requirements to manage the receipt and disbursement, and related assets and liabilities, of taxpayer accounts. The Joint Financial Management Improvement Program (JFMIP) identifies controls as part of its mandatory requirements for federal financial management systems. In its framework for Federal Financial Management Systems, the JFMIP states that “Effective financial management depends upon appropriate control of business transactions, in accordance with internal control standards, and recording business event information in a manner that satisfies multiple users and uses. The JFMIP states that Effective financial management depends upon appropriate control of business transactions, in accordance with internal control standards, and recording business event information in a manner that satisfies multiple users and uses.

The IRS EA defines several key concepts, in order to provide a better understanding of how and where custodial financial controls fit into the EA. These key concepts are:

The enterprise context diagram profiles the business environment in which the IRS operates. It describes the external entities with which the IRS interacts. These entities are organized hierarchically with summary-level entities sometimes broken down into second- and even third- level entities.

In general, the IRS’ Enterprise context diagram does not describe interactions among the multiple roles of organizations unless those interactions are applicable to IRS business. For example, a business is a taxpayer when it pays its income tax, and a business is an employer when that business withholds taxes from its employees and submits tax-related W-2 information to the IRS. The IRS Enterprise context diagram describes interactions between business taxpayers and the IRS and between employers and the IRS; it does not describe interactions between taxpayers and employers.

The external entities are organized hierarchically with top-level entities broken down into second-level and sometimes third-level entities. This hierarchical organization parallels the Enterprise Conceptual Data Model’s definitions of taxpayer and third party. The higher level external entities are listed below:

The EA describes linkages between every Tax Administration Services, Support Delivery of Services and Internal Management of IRS Resources business process as defined in the End-to-End Business Process Views.

The EA describes the enterprise-level, future-state functional requirements that will support the IRS. The Business Process Model includes:

The IRS EA describes processing threads that are used to demonstrate how system software applications are involved in executing high-level business processes. The processing threads consider aspects of processing tax returns and payments, initiating compliance actions, and providing customer support and taxpayer education. Third party support also is addressed. A security processing thread presented in Security Processing Thread emphasizes the involvement of infrastructure components as an employee logs on to an IRS workstation and begins working on a filing and payment compliance case. The following processing threads are discussed in the corresponding section in EA:

IRS Organization Descriptions, which are part of the IRS EA Organization Model View, identify and describe the organizational entities that comprise the IRS. The scope encompasses the entire IRS Enterprise, including advisory functions, such as Chief Counsel and the National Taxpayer Advocate, as well as all Operational Support components. The EA provides summaries of organization-level business concepts of operations (ConOps) that have been completed, processed, and approved for inclusion in the EA.

The purpose of the Role Definitions section is to identify and classify roles that support the core business of the IRS; it is not intended to be an exhaustive list of roles. While functional roles are identified, organizational roles are not identified, because these change over time. All identified roles contain role descriptions that define each role.

The Location Type Definitions identify and classify all of the distinct types of locations where IRS conducts business (directly or indirectly) or where critical functions are performed in support of IRS business or technical operations. These definitions establish the enterprise-wide terms, nomenclature, and hierarchical structuring of locations, so that consistent names and meanings are used across the enterprise. The focus is on functional and physical locations that are durable over time. The Location Types definitions do not try to define organizational locations, which tend to change over time. IRS business processes are associated with the specific IRS Location Types at which they are performed in Process / Location Type.

IRS Organizations use the business ConOps as a strategic framework in order to express their future state vision. An organization’s ConOps is typically a key driver of changes to any of the six domains of change – organization, location, business process, data, applications and/or technology. The intent of the ConOps framework is to:

The IRS EA Information Dictionary is located within the Glossary of IRS Business Terminology. It is divided into the Glossary defining all terminology and the Acronyms List defines acronyms used in the EA. These two glossaries are intended to be mutually exclusive. If a term does appear in both, the definition in the Glossary of IRS Business Terminology has precedence.

The Enterprise Conceptual Data Model (ECDM) is a high-level view of non-transient data needed for the administration of the business of the IRS. Data models of more than a few data classes are organized as a hierarchy of subject areas, each more narrowly defined than the subject area containing it, until they are small enough to allow comprehension of the entire subject area in a diagram or two. The ECDM is organized into three top-level subject areas, each of which also divides into three subject areas. The three top-level areas are:

The data architecture component of the EA addresses the key principles that affect the way that projects create and use data. Data architecture in the EA covers the following areas:

The technology architecture of the EA represents the hardware, system software, and network components needed to support the implementation of business system applications and application data. The technology architecture model view of the ELC represents the physical platforms and technical infrastructure that supports the operation and use of applications and data in the IRS.

In general, the IRS EA presents a multi-layer technology architecture. This supports a services approach that complies with the layered approach specified in the TRM. Much of the detailed architecture guidance around the technology architecture is provided in the IRS TRM manual. The TRM describes the technologies that will be assembled into a system to support the IRS Enterprise applications processing requirements.

The Systems Architecture is presented in two logical sections:

The System Requirements items detail the needs identified during a comprehensive systems analysis. It comprises the following seven topics:

The System Design items provides a high-level description of the design of the systems needed to satisfy the functional, performance, security and privacy, and system management requirements detailed in the System Requirements . It comprises the following three topics:

The IRS EA specifies the external and internal system interfaces. However due to the high-level nature of the EA, this discussion is limited to identification of the information exchanged on each system interface. Within this context, Communications Services discusses the network infrastructure elements and the technology needed to support the System Interfaces, and Enterprise Services discusses specific services supporting the System Interfaces.

The IRS EA provides a detail description of the IRS layers and interfaces, incorporating graphical detail depicting the IRS Enterprise Target Systems architecture. This description is intended to guide IRS projects in achieving and demonstrating their compliance with the Enterprise Architecture. The description is divided into following set of document segments, which are defined according to the IRS layers and interfaces:

The IRS EA provides an overview of the Technical Architecture from the perspective of the three technical views in the Enterprise Lifecycle (ELC) methodology. It provides high-level perspectives of the application architecture, the data architecture, and the conceptual technology architecture views. While the business architecture covers concepts related to business process, organization, and location, the technical architecture covers concepts and strategies related to data, applications, and technology. The ELC Domains of Change view of the EA is really a summarization of all the technical components of the EA as they guide the development of systems. Business drivers defined in the business architecture lead to the elaboration of functional and technical requirements. These are then used to develop a set of abstract systems, which in turn define a set of conceptual target-state applications that manage enterprise data on enterprise-approved technology platforms. The common architecture decisions for technology, application, and data model views (that is, the Technical Architecture) are documented in the Application Architecture (Official Use Only), Data Architecture, and Conceptual Technology Architecture models provided by the EA. The goals of defining these common decisions are to:

The Security Architecture models (work products) contained within the EA describe major security aspects of IRS logical business systems of the IRS Enterprise Target Architecture (ETA). There are two such models:

The EA provides a security risk assessment model that supports the Enterprise target systems security architecture. Specifically, this risk assessment estimates the relative degree of security risk associated with major system components. Two risk estimates are given: (1) for the component unprotected by any security mechanisms and (2) for the component protected by the security mechanisms described in the Allocation of Security Mechanisms to System Components model of the Security Architecture.

The IRS EA discusses Enterprise System Management (ESM) as the basis for designing and deploying a complete systems management capability at the IRS. This discussion supplies guidance regarding:

In the IRS EA, logical systems are defined across the Enterprise. As appropriate, Enterprise Functional Requirements and Data Requirements are allocated to these systems. The EA defines and describes allocation of functional and data requirements to systems. In addition, the EA provides:

The EA Guidance document provides guidance and practical reference for developers who are developing applications in compliance with the IRS Enterprise Architecture (EA). EA Guidance documents include Enterprise Data Standards and Guidelines (EDSG), Service-Oriented Architecture (SOA) Guidance, .NET Guidance, and Design patterns.

The IRS Online Service Repository captures the list of services and their descriptions contained in the IRS. It also provides information on service definition.

The IRS EA provides access to a collection of resources that describe service-oriented architecture (SOA) within the EA and support IRS projects in achieving and demonstrating their compliance with the EA.