Objectives: Introduction Over View of System Analysis and Design
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- 1.7 Systems Models
- 1.7.1 Schematic Models.
| Formal Information system A formal information system is based on the organization represented by the organization chart. The chart is a map of positions and their authority relationships, indicated by boxes and connected by straight lines. It is concerned with the pattern of authority, communication and workflow. Information is formally disseminated in instructions, memos, or reports from top management to the intended user in the organization. This structure also allows feedback up the chain of command for follow – up. In Figure 1-1 input form the environment provides impetus for policy decision by top management. Policies are generalizations that specify what an organization ought to do. Policies are translated into directives, rules and regulations and transmitted to lower-level management for implementation. The output represents employee performance. 1.7 Systems Models In no field are models used more widely and with greater variety than in systems analysis. The analyst beings by creating a model of the reality (facts, relationships, procedures, etc) with which the system is concerned. Every computer system deals with the real world, a problem area, or a reality outside itself. For examples, a telephone switching system is made up of subscribers, telephone handsets, dialing, conference calls, and the like. The analyst beings by modeling this reality before considering the functions that the system is to perform. Various business system models are used to show the benefits of abstracting complex system to model form. The major models are schematic, flow, static and dynamic system models. 1.7.1 Schematic Models. A schematic model is a two – dimensional chart depicting system elements and their linkages. Different arrows are used to depict information flow, material flow and information feedback. Various elements of the system are depicted inboxes. Download 0.94 Mb. Share with your friends:
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