Outline design, detailed design (ii) content of the design

3.1 main contents of the outline design

Different system types its outline design content is not the same, through the outline design guidelines we can determine the specific content of the outline design, but generally speaking, the content of the outline design can include the system architecture, module division, System interface, data design 4 main aspects of the content.

1.System architecture

The system architecture includes the software and hardware technology platform and related technology list, the physical structure of the system, the type of the physical device, the type of database management system, the type of the server, the subsystem partition and deployment method, the software architecture of the system, the third party software platform list, etc.

Example: Hardware architecture

Example: Software architecture: including hierarchy, subsystem & Module Division

Example: Software technology Platform

Software technology platforms typically define what software systems are used to implement specific functions, such as deploying services in a decentralized SOA architecture, resolving data communication and sharing with an ESB, interacting with the MVC structure, separating the business, and using RIA technology to support complex, Visual interaction, and so on.

Example: Subsystem Division

2.Module partitioning

The main work of module division is to divide, merge and group the functions into subsystems and function modules by dividing, merging, grouping and so on, and then fine-grained the function modules and function module according to the requirements of business domain and system. Module partitioning can be achieved in 2 steps, level and module design and process design.

The 1-step level design requires multiple layers of system partitioning for complex systems, and then a layer of design. The method of hierarchy division can combine the business, the deployment, the application function and other factors, first classify, then carry on the abstract analysis, tidy up the common elements, and summarize the function into the module. Methods of production methods can be used in a variety of representations, the following examples are in the form of graphs or tables produced.

Example hierarchy, module division

In the example, the system first divides the platform (province, city, terminal), the subsystem (Monitoring system, analysis System) in each platform, and defines the module (service) in the subsystem clearly.

Example hierarchy, module division

According to the business function division, at the same time, some common modules are abstracted after induction.

Step 2 of the process division, the design of the process between the modules. After the level and module partition is completed, the relationship between the modules needs to be described, which can include time series relation, state relation, data relation and so on. In the actual design, according to the situation can be described in different ways to produce the corresponding design documents, such as timing-based systems can use time series diagram.

After the module segmentation, the segmentation use case, the process. Design of inter-module process using time series diagram

3.Interface design

Software system in combination with business, function, deployment and other factors to gradually decompose the software system into the module, then the module and module must be based on the function of each module to define the corresponding interface. The interface design in the overview is primarily used for various interactions between subsystems/modules or internal systems and external systems. The content of interface design should include : function description, interface input and output definition, error handling and so on. The type of software system interface and specifications, there can be APIs, service interfaces, files, databases and so on, so the design method also has a great difference. But in general, the content of interface design includes: Communication method, protocol, interface invocation method, function content, input parameters, error /exception mechanism, etc. From the results point of view, the interface List (table) and detailed design information is necessary information.

Example . interface design for XML format of Web Service invocation

This interface defines the content of the data in terms of its format, meaning, type, and so on.

Example . Interface design of API call pattern

4.Data design

The modern software system and the information data are closely connected, especially the information system is mainly processing all kinds of data. In essence, all kinds of systems are the process of collecting, transforming, processing, re-converting and transmitting information. Isn't that right? Are these essential processes different from the human body system to our TV and cell phone systems? Software system data design, especially information system, mainly includes database design or completion of the core (library) table design, of course, in addition to database design also includes building in memory, files of the key data is also the design content.

ü Database design: Database logic design, physical design, capacity design, data dictionary, data deployment design and so on.

ü Data design: Configuration file design, temporary file design, memory data design (shared data design, content data structure design) and other content.

Example Database design (e-r diagram)

Example Data dictionary

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Example Memory design

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Example configuration file Design

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3.2The main content of detailed design

Detailed design is the continuation of the summary design, this continuation is reflected in the design granularity. In general, detailed design based on business requirements and outline design content, determine the refinement of various types of components of the function, logic flow, business requirements, component interface. From the process of basically follow the design of the 4 main activities, the specific operation can generally be summarized as module component segmentation, module component design, design common function 3 steps, wherein the component segmentation is more critical. The general information system, the main component classification may include the picture, the report, the service, the common component.

1.Screen design

Picture design is one of the main contents of interactive design. The common design content includes the screen at a glance corresponding to the picture migration relationship, the detailed picture function.

example, screen at a glance

example, picture migration

The picture migration mainly describes the action relation between the screen, and defines the entrance and exit of all the pictures.

Single screen Design

Prototype of the example screen

Action Definition for example screen

Example screen elements, processing definitions

2.Service Design

Service components corresponding software system mainly through the software interface to achieve the function of the module, detailed design of the main content of the service design includes the corresponding program module (package) design,class design, processing logic (timing relationship), internal and external interfaces, constraints and so on.

Example processing logic

Example class design

3.Joint design

The key step in the detailed design is to carry on the common design, the common design often greatly affects the subsequent development workload. For example, a system to extract 40% Common and only 10% of the common, development, testing the workload varies greatly. It is recommended that specific projects should be designed together as early as possible and effective. Common design can be broadly divided into business common, technology common.

ü Business is common with business-related, can be based on the characteristics of the business to identify and abstract different models to design, but some common common more easily identified, such as rights Management, basic (master) data management, user management, security management and so on. such as common e-commerce systems, including content (CMS) management, recommendation engine,TM,OSS,BI, payment, advertising management, etc. can be incorporated into the common design according to the situation.

U technology is generally related to computer technology, such as thread management, screen components,Log management, memory management, file processing, word processing, configuration management, encryption and decryption, log, message, exception, error handling and so on.

Examples of joint design

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Design of the example directory (configuration) structure

Outline design, detailed design (ii) content of the design