Coad and Yourdon Object-oriented design process

Coad and Yourdon continue to adopt the five levels (objects and classes, structs, attributes, services, and themes) mentioned in the object-oriented analysis phase during the design phase, which helps from analysis to design transitions. According to the object-oriented design method of Coad and Yourdon, the five levels are used in the design phase to establish four parts of the system: problem domain, user interface, task management and data management.

The design of the domain part of problem theory

The problem domain section includes all the classes and objects directly related to the application problems we face, and this work is actually beginning in the object-oriented analysis phase, where it needs to be further refined.

In the object-oriented analysis stage, we get the conceptual model related to the application, in the object-oriented design stage, we improve and add the result of the analysis. According to the change of demand, the class and object, structure, attribute and operation of the model generated in the object-oriented analysis stage are combined and decomposed, and the necessary classes, attributes and relationships are added according to the object-oriented design principle.

The design of the problem domain section includes:

(1). Reuse Design

(2). Correlate the grey matter of the problem domain.

(3). Adding generalized classes to establish the Inter-class protocol.

(4). Adjust the inheritance support level.

(5). Improve performance;

(6). Add the lower layer of the component.

Design of User Interface section

Usually in the object-oriented analysis phase of the required attributes and operations, in the object-oriented design phase must be based on the requirements of the details of the interaction into the design of the user interface, including effective human-computer interaction must be the actual display and input.

The design of the user interface is mainly composed of the following aspects:

(1). User classification;

(2). A script describing people and their tasks;

(3). Design command layer;

(4). Design the detailed interaction;

(5). Continue to expand the user interface prototype;

(6). Design Human-Computer Interaction Class (HIC);

(7). According to the graphical user interface design.

Design of Task Management Section

A task, a nickname for a process, is a procedure for performing a series of activities. When there are many concurrent behaviors in the system, it is necessary to classify various actions according to the coordination and communication relationship of each behavior. To achieve the purpose of simplifying the design and coding of concurrent behavior.

Task management mainly includes the selection and adjustment of tasks, and its work includes:

(1). Identify event-driven tasks;

(2). Identify the clock-driven task;

(3). Identify priority tasks and key tasks;

(4). Identify the coordinator between tasks;

(5) To evaluate each task to ensure that it can meet the process criteria of selecting tasks;

(6). Define each task, describe what it is, how it works, how it communicates.

The design of the Data Management Section

The Data Management Section provides the basic structure for storing and retrieving objects in a data management system, including access and management of persistent data.

There are three kinds of data management methods: file management, relational database management and object-oriented database management.

The Data Management section is designed to include:

(1). Data storage Design. Data storage Design Choose the way to store data: file storage, relational database form storage, or object-oriented database storage.

(2). Design the corresponding operation. Increase the properties and operations for storage management for each object and class that needs to be stored, described in the definition of classes and objects.