Requirement Analysis of Software Engineering 3

Demand analysis uses the logic model of the current system to export the logic model of the target system to solve the "what to do" problem of the target system.

The logic model of the target system is instantiated to obtain the physical model from a specific business domain.

The requirements of the software are summarized as follows:

The program flow diagram shows the process of Requirement Analysis:

Requirement analysis must be ableIt is sufficient to express and understand the information and function domains of the problem. It is necessary to break down and refine the problem in a hierarchical manner. It is necessary to provide the logical and physical views of the system.

The problem breakdown can be either horizontal or vertical:

In this phase, the key document is the requirement specification. Pay attention to the principles of Specification Description for software requirements:

1. separation of functions from reality, that is, to describe what to do rather than how to implement it ".

2. Processing-oriented specification language (or system definition language) is required)

3. If the software being developed is only one element of a large system, the whole system is also included in

Description of the Specification

4. The specifications must include the operating environment of the system.

5. Specification Description must be an cognitive model

6. specifications must be operable

7. Specification Description must allow incompleteness and allow expansion

8. Specification Description must be localized and loosely coupled