Various charts in the software development process __architecture

Turn from: http://blog.csdn.net/michelleqiao/article/details/5303256

1. Use Phase: Demand analysis

Tools: Use cases, flow diagrams, data dictionaries

A.use Case (use cases)

Use cases are a very important concept in UML, where the usage case is at the center of the entire software development process using UML.

So, what exactly is use case? In UML documentation, use cases are defined as the definition and description of a coherent functional unit of a system or subsystem without presenting the internal structure of a system or subsystem. It's a mouthful, right. In fact, use case is a description of the function of the system, but a use case is described as a part of the entire system function, this part must be logically relatively complete functional flow. Well There is nothing special about use case. How is this thing going to be a central place in development? In the development process of using UML, the requirements are expressed using use cases, the interface is designed with the aid of case, and many of the classes are found according to using case, and test instances are generated according to the use cases, including the management and assignment of the entire development, and are also based on use Case to organize. Oh, it's so important to use the case. Well, use the case is blown here, the concrete usage also must experience in the practice, "the use of the wonderful, keep the heart" also.

For each actor, he uses a certain function of the system, so we identify and analyze use cases, each one for each actor. For Todo User, we can easily identify two use Case:add task and Remove tasks. Todo user takes the initiative to use the system features described in these two usage case, so the relationship between the TODO user and the two use case is expressed in the arrow from the TODO user in our usage case diagram. For filesystem, we identified the same two use case, but this time the arrow points from the use case to filesystem, indicating that the filesystem is passive.

Use case can be described in a number of ways, we can use the natural language (English, Chinese, as you will), you can use the formal language (wow. It's so cool. , or you can use various illustrations. In UML, two graphs are usually used to describe the use case, which is the sequence diagram (Sequence Diagram) and the collaboration diagram (collaboration Diagram)

The use case consists of the following elements:

Name

Simple description

Event Flow

Relationship

Activity diagrams and state diagrams

Use case diagram

Special Needs

Former conditions

Post condition

B. Data Flow DiagramData Flow diagram: For short DFD, is to express the logic function of the system, the logic direction and the logic transformation process in the system, it is the main expression tool of the structural system analysis method and a graphical method for representing the software model.
The basic symbol of a data flow diagram means:
1. The rectangle represents the external entity of the data;
2. The rectangle of rounded corners represents the processing logic of the transform data;
3. Less the right side of the rectangle to represent the storage of data;
4. Arrows represent data flow.
There are several main elements in the data flowchart:
→: Data flow. A data flow is a path that data travels within a system, and is therefore composed of data that is fixed by a set of components. If the booking list by the passenger name, age, unit, ID number, date, destination and other data items. Because the data flow is the data in the flow, there must be flow, in addition to the data flow between the data stream without naming, the data stream should be named by noun or noun phrase.
-: Data source (endpoint). Represents an entity outside the system and can be a person, object, or other software system.
0: Processing of the data (processing). Processing is the unit of data processing, which receives certain data input, processes it, and produces output.
In: Data storage. Represents the static storage of information, which can represent a file, a part of a file, a database element, and so on.
In the case of a single data flow diagram, the following guidelines must be noted:
1. A processed output stream should not have the same name as the input data stream, even if their constituent components are the same.
2. Maintain data conservation. In other words, the data in a processing of all output streams must be obtained directly from the input stream of the processing, or through the data produced by the process.
3. Each processing must have both the input data stream and the output data stream.c. Data dictionaryA Data Dictionary (dictionary) is a directory of record database and application metadata that users can access. An active data dictionary is a data dictionary whose contents can be automatically updated by the DBMS when modifications are made to the database or application structure. A passive data dictionary is a data dictionary whose contents must be updated manually when modified.
The data dictionary is a reserved space, a database, which is used to store information in the database itself.
The data dictionary may contain information such as:
Database design Information
Stored SQL programs
User Rights
User statistics
Information in the process of the database
Database growth Statistics
Database Performance Statistics
The data dictionary is the collection of various data descriptions in the system, and it is the main result of the detailed data collection and data analysis.
The data dictionary usually includes five parts of the data item/data structure/stream/data storage and processing process.
A data dictionary is a collection of information about data, which is a collection of definitions of all the elements contained in the diagram.
The composition of the Data dictionary:
1. Data item
2. Data structure
3, Data flow
4. Data storage
5, processing process
Data dictionary
An important part of the database is the data dictionary. It holds information about the database and is a set of read-only tables for the user. Data dictionary content includes:
1. Information about all schema objects in the database, such as tables, views, clusters, and indexes.
2, how much space is allocated, how much space is currently used.
3, the default value of the column.
4, the integrity of the constraint information.
5, the user's name.
6, the user and role are granted permissions.
7, user access or use of audit information.
8, the other generated database information.
A database data dictionary is a set of tables and view structures. They are stored in the system table space.
The database data dictionary is not only the center of each database. It is also very important information for each user. Users can access the database data dictionary using SQL statements.
Information about the data collection, is a user can access the record database and application metadata directory, is the table information in the database physical and logical description

2. Use stage: The design of the work body

Tools: Hierarchy diagrams, Structure diagrams

A. Hierarchy Map

Province

B. Structure diagram structure diagram: Refers to the module's call relations as the Clue, uses the Top-down line to represent the call relations and indicates the parameter transmission direction and the content, from the macroscopic reflection software hierarchical structure graph.

3. Use stage: detailed design

Tools: HiPo Diagram

A.hipo HiPo diagram--another graphical tool for representing software architecture
The HIPO (hierarchy Plus input/processing/output) diagram is a tool that represents the architecture of software systems developed by IBM in the 70 's. It can describe the total module hierarchy of the software--h graph (level diagram), but also can describe each module input/output data, processing functions and module call Details--ipo diagram. The HiPo diagram is based on the hierarchy of module decomposition and the three basic parts of module internal input, processing and output.
It is a tool that represents the structure of a software system. The HiPo diagram is based on the hierarchy of module decomposition and the three basic parts of module internal input, processing and output.
1. h Diagram of HiPo graph
Used to describe the hierarchy of the software, the rectangular box represents a module, the line between the rectangles represents the invocation relationship between the modules, and the call order is not indicated as the structure diagram.
2. IPO Map
H diagram only shows that the software system consists of those modules and its control hierarchy, does not indicate the information between the modules and the internal processing of the module. Therefore, some important modules must also be based on data flow diagram, Database dictionary and H graph to draw specific IPO map.
How to draw various graphs: http://blog.csdn.net/sgear/article/details/

UML Basics

Http://v.youku.com/v_show/id_XNDk5NTc2NDg=.html

Visio draws UML sequence diagrams (primary)

Http://v.ku6.com/show/YWCtNDnbF9FkMFbh.html

Visio draws UML State diagrams

Http://v.ku6.com/show/foj5GWgdUYQV33jC.html

Drawing of Visio UML component diagrams

Http://v.ku6.com/show/4MMkoLFzCu4Eh6Tt.html

Drawing of Visio UML collaboration diagrams

Http://v.ku6.com/show/LLnB0xD_vaT_RnFK.html

Drawing of Visio UML subordinate diagrams

Http://v.ku6.com/show/zuXQJwnyhyiKtb8n.html

Drawing of Visio UML activity diagrams

Http://v.ku6.com/show/J3IYBFzITf3hRrhb.html

Visio Data Graphics Tutorial

Http://v.youku.com/v_show/id_XMjkyMjE4MzM2.html