What is system design?

Question 1: What is the purpose of system design? System design is considered as the research and development stage in the system life cycle.

There is only one goal of research and development: to obtain high-quality products that meet business needs within the cost range.

The direct goal of system design is to form the logical structure model of the system. Specifically, it includes: the choice of architecture, technology and so on; In the specific design process, depending on the business purpose, index requirements and resources, its ultimate goal is to obtain high-quality products that meet the business requirements within the cost range.

For example, the application of layer, the basic logic system of data layer, business layer and interface layer is often and necessary. But not with this system?

In extreme cases, it is assumed that the goal of development is only a small tool, just a transitional tool, and it needs to deal with an abnormal data in the connection period between the old and new systems. Small transition tools that are not needed after a new system is put into use need to be applied immediately without reusing resources.

As a designer, should we choose a layered system at this time?

Don't forget the ultimate goal: to obtain high-quality products that meet business needs within the cost range.

Question 2: What is the significance of overall system design? System design should be carried out from top to bottom. Design the whole structure first, and then deepen it step by step until each module is designed. The overall design mainly refers to the reasonable arrangement of the division (subsystem), the configuration of mechanical equipment (including software and hardware equipment), the storage law of data and the realization planning of the whole system on the basis of system analysis.

First, the task of system design

1. The concept of system design

System design, also known as physical design, is the second stage of developing management information system. System design can usually be divided into two stages. First, the overall design, whose task is to design the framework and overview of the system, and make detailed declaration and approval to the user units and leading departments, and then carry out the second stage DD detailed design on this basis. These two parts are interrelated and need to be carried out alternately. This chapter introduces these two parts together.

System design is the work of developers, who convert the logical model of the target system obtained in the system design stage into the physical model of the target system, and the DD system design specifications obtained in this stage are the working basis for the next stage of system realization.

2. Main contents of system design

The main task of system design is to carry out overall design and detailed design. Their specific contents are explained as follows.

(1) overall design

The overall design includes system module structure design and computer physical system configuration scheme design.

System module structure design

The task of system module structure design is to divide subsystems, then determine the module structure of subsystems and draw the module structure diagram. In this process, the following questions must be considered:

How to divide a system into multiple subsystems;

How to divide each subsystem into multiple modules;

How to determine the data transmitted between subsystems and modules and their calling relationship;

How to evaluate and improve the quality of module structure?

Configuration scheme design of computer physical system

In the overall design, the specific configuration scheme of computer physical system should be designed to solve the problems of computer software and hardware system configuration, communication network system configuration, computer room equipment configuration and so on. The specific configuration scheme of computer physical system must be approved by the user and the leading department before it can be implemented.

A large number of experiences and lessons in developing management information systems show that the selection of computer hardware and software equipment can not only look at advertisements or information introduction, but also must be fully investigated and studied. It's best to know the operation situation, advantages and disadvantages of the units that have used software and hardware equipment, and solicit the opinions of relevant experts, and then demonstrate and finally write a report on the configuration scheme of computer physical system.

Judging from the actual situation in China, many units buy computers before deciding to develop them. This unscientific and blind approach is not desirable and will cause great waste. Because computers are updated very quickly, that is, computer equipment is purchased in the early stage of development and the middle and late stage of system implementation, and the price difference will be great. Therefore, in the process of developing management information system, the configuration scheme of computer physical system should be designed in the overall design stage of system design.

(2) Detailed design

On the basis of the overall design, the second step is detailed design, mainly including process design, and determining the detailed implementation process within each module, including local data organization, control process, and specific processing requirements of each step. Generally speaking, the detailed design of process modules is not too difficult. The key is to describe the implementation process of each module in an appropriate way, such as flow chart, problem analysis chart, IPO chart, process design language and so on. In addition to process design, there are code design, interface design, database design, input and output design and so on.

(3) write the system design specification

The result of the system design stage is the system design specification, which is mainly composed of detailed design contents such as module structure diagram and module specification. ...& gt& gt

Question 3: What is the overall design of the system? System design should be carried out from top to bottom. Design the whole structure first, and then deepen it step by step until each module is designed. The overall design mainly refers to the reasonable arrangement of the division (subsystem), the configuration of mechanical equipment (including software and hardware equipment), the storage law of data and the realization planning of the whole system on the basis of system analysis.

First, the task of system design

1. The concept of system design

System design, also known as physical design, is the second stage of developing management information system. System design can usually be divided into two stages. First, the overall design, whose task is to design the framework and overview of the system, and make detailed declaration and approval to the user units and leading departments, and then carry out the second stage DD detailed design on this basis. These two parts are interrelated and need to be carried out alternately. This chapter introduces these two parts together.

System design is the work of developers, who convert the logical model of the target system obtained in the system design stage into the physical model of the target system, and the DD system design specifications obtained in this stage are the working basis for the next stage of system realization.

2. Main contents of system design

The main task of system design is to carry out overall design and detailed design. Their specific contents are explained as follows.

(1) overall design

The overall design includes system module structure design and computer physical system configuration scheme design.

System module structure design

The task of system module structure design is to divide subsystems, then determine the module structure of subsystems and draw the module structure diagram. In this process, the following questions must be considered:

How to divide a system into multiple subsystems;

How to divide each subsystem into multiple modules;

How to determine the data transmitted between subsystems and modules and their calling relationship;

How to evaluate and improve the quality of module structure?

Configuration scheme design of computer physical system

In the overall design, the specific configuration scheme of computer physical system should be designed to solve the problems of computer software and hardware system configuration, communication network system configuration, computer room equipment configuration and so on. The specific configuration scheme of computer physical system must be approved by the user and the leading department before it can be implemented.

A large number of experiences and lessons in developing management information systems show that the selection of computer hardware and software equipment can not only look at advertisements or information introduction, but also must be fully investigated and studied. It is best to know the running situation, advantages and disadvantages of the units that have used software and hardware equipment, and solicit the opinions of relevant experts, and then demonstrate and finally write a report on the configuration scheme of computer physical system.

Judging from the actual situation in China, many units buy computers before deciding to develop them. This unscientific and blind approach is not desirable and will cause great waste. Because computers are updated very quickly, that is, computer equipment is purchased in the early stage of development and the middle and late stage of system implementation, and the price difference will be great. Therefore, in the process of developing management information system, the configuration scheme of computer physical system should be designed in the overall design stage of system design.

(2) Detailed design

On the basis of the overall design, the second step is detailed design, mainly including process design, and determining the detailed implementation process within each module, including local data organization, control process, and specific processing requirements of each step. Generally speaking, the detailed design of process modules is not too difficult. The key is to describe the implementation process of each module in an appropriate way, such as flow chart, problem analysis chart, IPO chart, process design language and so on. In addition to process design, there are code design, interface design, database design, input and output design and so on.

(3) write the system design specification

The result of the system design stage is the system design specification, which is mainly composed of detailed design contents such as module structure diagram and module specification. ...& gt& gt

Question 4: What are the main tasks of system design? 10 is safe and conducive to development.

Question 5: What is the design of the indication system? Indicating system is the function guide of public space and the symbol of public space civilization. It belongs to the new design category of indication system in China. Many spaces such as cities, buildings, urban road traffic, commercial blocks and so on need systematic planning. The design business of the indication system designed by Shanghai Shangzhi includes: functional area planning, vehicle traffic analysis, pedestrian traffic analysis, user search comfort analysis, guide map design, logo design, indication icon design and ground logo design.

Question 6: What is system architecture design? The responsibilities of architects are mainly as follows:

1. Confirm requirements

In the process of project development, after the requirement specification is completed, the architect participates in it, and the requirement specification must be approved by the architect. Architects need to communicate with analysts repeatedly to ensure that they fully and accurately understand the needs of users.

2. System decomposition

According to the needs of users, architects break down the whole system into smaller subsystems and components, thus forming different logical layers or services. Then, the architect will determine the interface of each layer and the relationship between layers. Architects should not only divide the whole system vertically, but also divide the same logical layer horizontally.

The skill of software architect is basically reflected here, which is a complicated job.

3, technology choice

Through a series of decomposition of the system, the architect finally formed the overall architecture of the software. The choice of technology mainly depends on the software architecture.

Is the Web server running Windows or Linux? Is the database MSS, Oracle or Mysql? Do you need to adopt a lightweight framework such as MVC or Spring? Is the front end rich or thin? Similar work needs to be proposed and evaluated at this stage.

The architect's choice of products and technologies is limited to evaluation, and there is no decision. The final decision belongs to the project manager. The technical scheme proposed by the architect provides important reference information for the project manager, who will weigh the actual situation of the project budget, human resources and time schedule and finally confirm it.

4, formulate technical specifications

Architect is the technical authority in the process of project development. He needs to coordinate all developers, keep communication with developers, and always ensure that developers realize various functions according to their architectural intentions.

Architects should keep in touch not only with developers, but also with project managers, requirements analysts and even end users. So for architects, there are not only technical requirements, but also interpersonal requirements.

Question 7: What should be included in the system design report? Main contents of system design

The system design is divided into general structure design and detailed structure design.

(1) The overall structure design mainly solves the problems of subsystem division and confirmation, module structure design, network design and configuration scheme.

(1) subsystem division: a complex system design is transformed into several subsystems and a series of basic module designs, and the decomposed subsystems and modules are connected according to the hierarchical structure through the module structure diagram.

② Module structure design: It is to refine each subsystem, determine the module structure of the divided subsystem, and draw the module structure diagram.

③ Network structure design and equipment configuration scheme: It is to consider how to connect each subsystem with the local area network from the inside, and how to connect the system with the external system in the future, and configure and select network products according to the actual situation.

(2) Detailed structural design mainly solves the problems of code design, output design, input design, processing design, database design, man-machine interface design and safety control design.

① Coding design: It is to design an optimized information coding system that can be shared by all parts of the system.

② Output design: It is to design various output modes according to the needs of management and users, such as report output, disk file output, graphic output, etc.

③ Input design: it is to design the input style of the system as required, such as input mode design, proofreading mode design, input interface design and input interface layout.

(4) Process design: design according to module division, with the purpose of mastering the whole process of system processing and facilitating design work such as input and output.

⑤ Database design: It is to make the whole system call and manage the required data quickly, conveniently and accurately.

⑥ Man-machine interface design: Provide a friendly interactive interface for users and managers of the system, which is convenient for access, operation and management.

⑦ The safety control design factory carries out safety protection from the aspects of software and hardware to ensure the normal operation of the system and reduce the losses caused by various safety problems.

Question 8: What are the main activities in the system design stage? The system design stage mainly includes:

Overall structure design of 1. system

2. Code and data file design

3. Design of subsystem function module

4. Process flow design

System design is the physical design stage of the new system factory. According to the logical model and functional requirements of the new system determined in the system analysis stage, a scheme that can be implemented in the computer network environment is designed under the environmental conditions provided by users, that is, the physical model of the new system is established.

Question 9: What is the purpose of system design? 1) Determine how to use the system;

2) Determine the composition and deployment mode of the system;

3) Determine the development steps of the system;

4) Determine the test steps of the system;

5) Select the system scheme and investigate the risks of the scheme;

Question 10: What is architecture? Architecture generally refers to software architecture.

Software architecture is a series of related abstract patterns, which are used to guide the design of large-scale software systems in all aspects. Software architecture is a sketch of the system. The object described by software architecture is an abstract component that directly constitutes the system. The connection between components clearly and relatively carefully describes the communication between components. In the implementation phase, these abstract components are refined into actual components, such as a specific class or object. In the object-oriented field, the connection between components is usually realized through interfaces (computer science). Software architecture is the basis of constructing computer software practice. Just as architects set the design principles and objectives of construction projects as the basis for draftsmen to draw pictures, software architects or system architects state the software architecture as the basis of actual system design schemes to meet the needs of different customers.

Software architecture is an easy concept to understand, and most engineers (especially those with little experience) will know it intuitively, but it is difficult to give an accurate definition. In particular, it is difficult to clearly distinguish between design and architecture: architecture is an aspect of design, which focuses on some specific characteristics.

In Introduction to Software Architecture, David Garland and Mary Shaw think that software architecture is a design level related to the following problems: "In addition to computing algorithms and data structures, designing and determining the overall structure of the system has become a new problem. Structural problems include the overall organizational structure and global control structure; Communication, synchronization and data access protocols; Function allocation of design elements; Logistics; Composition of design elements; Calibration and performance; The choice of alternative design. " GS93

But architecture is more than just a structure; IEEE Architecture Working Group defines it as "the highest concept of a system in its environment". The framework also includes "conforming" to system integrity, economic constraints, aesthetic needs and styles. It not only pays attention to internal considerations, but also considers the whole system in the user environment and development environment of the system, that is, it pays attention to external considerations at the same time.

In the process of Rational unification, the architecture of software system (at a given point) refers to the organization or structure of important components of the system, which interact with components composed of decreasing components and interfaces through interfaces.

As far as the connection with purpose, theme, material and structure is concerned, the software architecture can be compared with the architecture of buildings. Software architects need extensive software theoretical knowledge and corresponding experience to realize and manage the advanced design of software products. Software architects define and design software modularity, interaction between modules, user interface style, external interface methods, innovative design features, and object operations, logic and processes of high-level things.

Generally speaking, the architecture of a software system has two elements:

? It is the highest level division of software system from whole to part.

A system is usually composed of components, and how these components form and interact with each other is important information about the structure of the system itself.

Specifically, it should include architecture components, connectors and task flows. The so-called architectural elements are the core bricks of the system, while connectors describe the communication paths, communication mechanisms and expected results between these components, and task flow describes how the system uses these components and connectors to complete a certain requirement.

? The highest-level and hard-to-change business and technical decisions made to build a system.

Before building a system, many important decisions need to be made in advance, and once the system starts to be designed or even built in detail, these decisions are difficult or even impossible to change. Obviously, such a decision must be the most important decision related to the success or failure of system design, which must be studied and investigated very carefully.

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