Government Information Technology Agency
TITLE: Data Modeling
P740-S740 Rev 2.0 Effective Date: October 31, 2007
AUTHORITY The Government Information Technology Agency (GITA) shall develop, implement and maintain a coordinated statewide plan for information technology (IT) (A.R.S. § 41-3504(A (1))), including, the adoption of statewide technical, coordination, and security standards (A.R.S. § 41-3504(A (1(a)))). PURPOSE Data modeling is the formalization and documentation of existing processes and events that occur during application software design and development. It simplifies the complex process of software design, making a "blueprint" for construction. The purpose of this standard is to establish guidelines for budget unit and State implementations of data modeling that facilitate common, interoperable representations and descriptions of data and information that is collected and managed. SCOPE This applies to all budget units. A budget unit is defined as a department, commission, board, institution or other agency of the state receiving, expending or disbursing state funds or incurring obligations of the state including the Arizona Board of Regents but excluding the universities under the jurisdiction of the Arizona Board of Regents, the community college districts and the legislative or judicial branches. A.R.S. § 41-3501(2). The Budget Unit Chief Executive Officer (CEO), working in conjunction with the Budget Unit Chief Information Officer (CIO), shall be responsible for ensuring the effective implementation of Statewide Information Technology Policies, Standards, and Procedures (PSPs) within each budget unit.
STANDARD Data modeling is the graphical mapping of data/information in its relations to IT software application systems, sub-systems, and processes that gather, manage, transform, and communicate such data/information. Data modeling is an important component of systems development and re-engineering that can ensure that business functionality is complete and correct, end-user needs are met, and program design supports requirements for scalability, robustness, security, extensibility, and other characteristics, before implementation in programming code renders changes difficult and expensive to make. 4.1. In accordance with the implementation criteria defined in Statewide Policy P740, Data/Information Architecture, when required, budget units shall complete, and subsequently update throughout the development cycle of the IT project, a high-level physical data flow diagram (DFD) for the IT project’s
Standard P740-S740 Rev 2.0 Data Modeling
Effective: October 31, 2007 Page 2 of 8
software application, such as illustrated in Attachment A, Data Modeling Symbols, Definitions, and Samples. 4.1.1. Physical DFDs are required for top-level systems (parents) and subsystems (children) and shall depict the IT project’s data flows, data stores, data processes, and external entities (data sources/destinations). • A physical DFD provides a holistic, graphical representation of the flow of data into and out of processes implemented by software application systems and their respective subsystems. • A physical DFD focuses on the data being passed through processes to identify origination, transformation, and destination of data; data stores; and entity relationships as a result of business events and activities. • The physical DFD depicts the way a software application system will implement and execute the processes, independent of specific hardware and software. 4.1.2. Logical DFDs shall be required only when their creation is determined to benefit the IT project, budget unit, community of interest, or the State. The State CIO, in agreement with the Budget Unit CIO, shall make the determination of benefit as well as the mutually agreed-upon deliverables. • Logical DFDs are a further breakdown (decomposition analysis or leveling of subsystems)...