Data and Process Modeling and Object Modeling
With requirements defined, a system analyst focuses on how system data is transformed into useful information. The deliverable of data and process modeling is a logical model. A logical model shows what the system must do, regardless of how it will be implemented physically. Later, in the systems design phase, a physical model is built that describes how the system will be constructed. Data and process modeling involves three main tools:
- data flow diagrams
- a data dictionary
- process descriptions
In contrast, object-oriented (O-O) analysis describes an information system by identifying things called objects. An object represents a real person, a place, an event, or a transaction. For example, when a patient makes an appointment to see a doctor, the patient is an object, the doctor is an object, and the appointment itself is an object.
Object-oriented analysis is a popular approach that sees a system from the viewpoint of the objects themselves as they function and interact. The end product of O-O analysis is an object model, which represents the information system in terms of objects and O-O concepts. Object-oriented analysis provides us with another way to view and model system requirements.
At the end of this week, you will be able to:
- Describe data and process modeling concepts and tools, including data flow diagrams, a data dictionary, and process descriptions
- Describe the symbols used in data flow diagrams and explain the rules for their use
- Draw data flow diagrams in a sequence, from general to specific
- Explain how to level and balance a set of data flow diagrams
- Describe how a data dictionary is used and what it contains
- Use process description tools, including structured English, decision tables, and decision trees
- Describe the relationship between logical and physical models
- Explain how object-oriented analysis can be used to describe an information system
- Define object modeling terms and concepts, including objects, attributes, methods, messages, classes, and instances
- Explain relationships among objects and the concept of inheritance
- Draw an object relationship diagram
- Describe Unified Modeling Language (UML) tools and techniques, including use cases, use case diagrams, class diagrams, sequence diagrams, state transition diagrams, and activity diagrams
- Explain the advantages of using CASE tools in developing the object model
- Explain how to organize an object model
- Read Module 5: Data and Process Modeling.
- Participate in Module 5 SCR Case Simulation: Data and Process Modeling.
- Read Module 6: Object Modeling.
- Participate in Module 6 SCR Case Simulation: Object Modeling.
- Take the Unit 5 Test.
- Take the Unit 6 Test.
- Complete System Requirements Document - Project #1.