【Information System Project Manager】Information System Development Method

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Structured approach

1. Definition: The structured method is also called the life cycle method, which is a traditional information system development method.

2. Composition:
   1. Structured Analysis (SA)
   2. Structured Design (SD)
   3. Structured Programming (SP)

3. Essence: top-down, gradual refinement and modular design

4. Main features
   1. Clarification of development goals 2. Phased
   development of work
   3. Planning of development documents
   4. Structured design methods

5. Applicable scenarios: especially suitable for problems in the field of data processing

6. Inapplicable scenarios: Not suitable for large-scale and more complex system development

7. Disadvantages
   1. Long development cycle
   2. Difficult to adapt to changes in demand
   3. Little consideration of data structure

Object-oriented approach

1. Definition: The Object-Oriented (OO) method believes that the objective world is composed of various objects (everything is an object)

2. Connection with the structured method: Similar to the structured method, the OO method is also divided into stages, but there is no "gap" between the three stages of system analysis, system design, and system realization, that is, the boundaries of these three stages change Unclear

3. OO advantages:
   1. The OO method makes the description of the system and the representation of the information model correspond to the objective entities, which is in line with people's thinking habits.
   2. It is conducive to the communication and communication between users and developers in the system development process, and shortens the development cycle

4. OO Disadvantages: Must rely on certain OO technical support, has certain limitations in the development of large projects, and cannot be involved in the previous development links of system analysis

5. Application scenarios: At present, the development of some large-scale information systems usually combines structured methods and OO methods. First, use a structured approach to make a top-down overall division; then, use the OO method to develop from the bottom up

Prototyping method

1. Definition: The prototyping method is also called rapid prototyping, or prototyping for short. It is a method of rapid development of an information system based on the initial needs of users and using system development tools to quickly build a system model and show it to users, communicate with users on this basis, and finally realize user needs.

2. Classification:
   1. Whether to realize functional division: horizontal prototype; vertical prototype
   2. final result division: discard prototype; evolutionary prototype

3. Development process
   1. Determine the basic needs of users
   2. Design the initial prototype of the system
   3. Trial and evaluate the prototype
   4. Modify and improve the prototype
   5. Organize the prototype and provide documentation

4. Features
   1. The prototype method can shorten the system development cycle, reduce costs and risks, accelerate the speed, and obtain higher comprehensive development benefits.
   2. The prototype method is user-centered to develop the system, and the degree of user participation is greatly improved. The system meets the needs of users, thereby increasing user satisfaction and improving the success rate of system development.
   3. Because users participate in the whole process of system development, the functions and structure of the system are easy to understand and accept, which is conducive to the transfer of the system , Which is conducive to the operation and maintenance of the system

5. Insufficiency: high development environment requirements; high management level requirements

6. Applicable scenarios: suitable for system development with unclear requirements. In fact, for systems that are difficult to analyze and not technically difficult, they are suitable for prototype development. For systems where the technical level is far more difficult than the analysis level, the prototype method should not be used.

Service-oriented approach

1. Background: The application of OO is built on classes and objects, and the subsequently developed modeling technology groups related objects according to business functions, forming the concept of Component

2. The way of interaction:
   Interface: For cross-component function calls, they are exposed in the form of interfaces. Further decoupling the definition and implementation of the interface gave birth to service and service-oriented (Service-Oriented, SO) development methods

3. Advantages
   1. Improve system reusability
   2. Information resource sharing
   3. Interoperability between systems