Design refers to the design of the software system architecture, data structure, modules, etc., to establish a bridge between requirements and code; development refers to software engineers to code development according to system design, and unit testing, code inspection optimization.

1. The design work should follow the following principles:

1) Correctly and completely reflect the requirements of the Product Requirements Specification, fully considering its functions, performance, security, error handling and other needs.

2) Ensure the design's comprehensibility, traceability, testability, interface openness and compatibility, consider robustness (easy to modify, expandable, portable), and reusable;

3) Adopt a design method suitable for the project. If the system uses new tools and technologies, it needs to be prepared in advance; consider choosing the appropriate programming language and development tools;

4) Learn from previous design lessons and avoid recurring similar or similar problems;

5) For experienced and complex parts, designers with considerable experience are required;

6) Consider multiplexing from mature projects.

2. Design method

On the basis of fully understanding the product requirements, the software engineer selects the appropriate design method according to the Product Requirements Specification.

3. Software design process

Need to write the "Software Design Specification". The Software Design Specification should include the following: module description, function, parameter description, performance, process logic, algorithm, etc.

The Software Design Specification and related documentation should be reviewed.

4. Encoding Enter the encoding phase.  Coding Standards:

5. Unit testing Each module of the coded system should be unit tested.

6. Code check It is best to arrange for other software personnel to do it.