SSADM is a method developed in Great Britain and accepted in as a national standard for information systems development and analysis. SSADM is based on Data Flow Diagrams and is characterized with presence of clear sequence of steps at projecting, analysis, and documenting of information system. It involves 6 main stages: analysis of existing system or estimation of practicability, requirements definition, determination of technical requirements and equipment cost, development of logical data model, projecting of logical requirements and specification them, physical projecting. Each of them is also divided into several steps defining the tasks that should be fulfilled at a given stage. Gane Sarson Diagram The Gane-Sarson methodology uses the graphical techniques for building the logical models for the systems.
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Designing a human-computer interface is beyond the scope of Computer Science Graphical user interface libraries are currently not standardized at all , so the details concerning them will vary from system to system.
However, the Java user interface library is currently regarded as being well designed, and information about it is freely available.
The criteria for object-oriented designs seem less specific or concrete than the criteria for structured designs, but they do seem to be worth noting. Coupling Coupling describes the level of interaction between or among components of an object-oriented design, just as levels of coupling could be used to assess the interaction between components of a structured design. Interaction Coupling Interaction Coupling refers to connections between classes due to message connections.
Most references recommend that this be kept as simple and limited as possible; Coad and Yourdon go a bit further, by giving a more precise guideline Object-Oriented Design, Section 8. Inheritance Coupling Inheritance Coupling refers to the connection between generalizations and specializations in a generalization-specialization structure. Cohesion Cohesion of components of an object-oriented design is similar to the concept of cohesion of modules in a structured design. As defined by Coad and Yourdon, cohesion is the degree to which the elements of a portion of a design contribute to the carrying out of a single, well-defined purpose.
The Coad and Yourdon Method
Oracle Database Tips by Donald Burleson Object-oriented Analysis Object-oriented analysis starts with a traditional structured specification, and adds the following information: A list of all objects - A list describing the data contents of each noun, or physical entities in the DFD. A list all system behaviors - A list of all verbs within the process names such as Prepare order summary report, generate invoices, etc. A list of the associate the primary behaviors services with each object - Each object will have behaviors which uniquely belong to the object. Other objects may request the behavior of the object. A description of the contracts in the system - A contract is an agreement between two objects, such that one object will invoke the services of the other. A behavior script for each object - A script describes each initiator, action, participant, and service.
Yourdon and Coad Design Software with Rich Examples and Templates