| As described in the Introduction, in 1987 John Zachman published his ideas about the body of information that constitutes the system development effort. In his "Framework for information systems development" he made several observations about the system development life cycle: -
First, he doesn't look at the "phases" or "steps" in the effort. Instead, he is interested in the perspective of each set of players in the development process. It is, he asserts, as important to recognize that systems are developed by distinct groups with different points of view as it is to see the movement of systems from one step to another. -
Second, he addresses more than data and functions. In his original article he established a matrix that encompasses, for each perspective, not only data and function but also location. Then, in 1992, he and John Sowa extended it to include people, timing, and motivation. The framework architecture is a matrix, where the rows represent the different perspectives and the columns the things viewed from each perspective. Mr. Zachman's original "Framework" is shown in Appendix A. For reasons explained below, a modified version of this Framework is diagramed in Figure 1.1. Figure 1.1. The Architecture Framework.  The Rows The rows represent the points of view of different players in the systems development process, while columns represent different aspects of the process. The perspectives are: -
Scope (planner's view) : This defines the enterprise's direction and business purpose. This is necessary in order to establish the context for any system development effort. It includes definitions of the boundaries of system development or other development projects. -
Enterprise model (business owner's view) : This definesin business termsthe nature of the business, including its structure, processes, organization, and so forth. -
Model of fundamental concepts (architect's view) : This row, called the "information-system designer's view" in Mr. Zachman's version, defines the business described in Row Two, but in more rigorous terms. Where Row Two describes business processes, as perceived by the people performing them, Row Three describes the underlying functions each process addresses. For example, where Row Two saw "Issue purchase order", Row Three sees this as "Place order". These functions are then expressed specifically as transformations of data. Similarly, where Row Two described all the things of interest to the enterprise, Row Three describes the fundamental things about which the organization wishes to collect and maintain information. The Row Three "things" are those of which the Row Two things may be but examples. Note that, to arrive at this view, it is necessary to examine the fundamental structures that lie below the business owners ' views of the enterprise. -
Technology model (designer's view) : This describes how technology may be used to address the information-processing needs identified in the previous rows above. Here object-oriented databases are chosen over relational ones (or vice versa), kinds of languages are selected and program structures are defined, user interfaces are described, and so forth. -
Detailed representations (builder's view) : The builder sees the details of the particular language, database storage specifications, networks, and so forth. -
Functioning system : Finally, a new view is presented to the organization in the form of a new system. The Columns The columns in the architecture framework represent different areas of interest for each perspective. The columns describe the dimensions of the systems development effort. These are: -
Data : Each row in this column addresses understanding and dealing with the things of significance to an enterprise, about which information is to be held. In Row One this is about the most significant objects dealt with by the enterprise. In Row Two it is about the language used, and in Row Three it is about specifically defined entity types and their relationships to each other. In Row Four this concerns the representation of data by computer software and database management systems. This may be in terms of tables and columns, object classes, and the like. In Row Five it is about the way data are physically stored on the computer, in terms of tablespaces, disk drive cylinders , and so forth. -
Activities ("Function" in Mr. Zachman's original Framework) : The rows in the second column are concerned with what the enterprise does to support itself. This is the enterprise's mission in Row One, the strategies, tactics, and business processes used to carry out that mission in Row Two, and the underlying functions the strategies and tactics implement in Row Three. Row Four concerns program functions, and the Row Five perspective is of the specifics of programming languages implementing the program functions. -
Locations ("Network" in Mr. Zachman's original Framework) : This column is concerned with the geographical distribution of the enterprise's activities. In Row One it is concerned with the parts of the world where the enterprise operates. In Row Two it is concerned specifically with the enterprise's various offices and how they are related to each other. In Row Three it is concerned specifically with the roles played in each location, and how they relate to those in other locations. Row Four is about the network of computers and communications, while Row Five is about the protocols and particular components of a communications network. -
People and organizations : This column describes who is involved in the business and in the introduction of new technology. Row One addresses the enterprise's attitudes and philosophy concerning the management of human resources. Row Two is concerned specifically with the positions people hold and how they are related to each other. The architect's row addresses the fundamental nature of human organizations. This includes the actual and potential interactions between people and functions. Row Four is concerned with the design of man-machine interfaces, while Row Five, in conjunction with the activities column, is concerned with the programming of those interfaces and security steps. -
Timing : This column describes the effects of time on the enterprise. This includes annual planning at Row One, business events at Row Two, and data-related events at Row Three. Row Four translates the data-related events into system triggers. Row Five is concerned with the implementation of those triggers. -
Motivation : As Mr. Zachman originally described this column, it concerned the translation of business goals and strategies into specific ends and means. This description has since been expanded to include the entire set of constraints (business rules) that apply to an enterprise's efforts. Row One is concerned with the enterprise's vision and mission; Row Two addresses its goals, objectives, strategy, and tactics, as they are translated into business policies and business rules. Row Three addresses the specific articulation of business rules in terms of their effects on data and activities. Row Four is about the design of the programs that will implement those effects, and Row Five is about the construction of those programs. |
