(1) Software is an information product that is intangible, abstract, replicable and shareable. Compared with hardware, software is a logical entity rather than a physical entity. It can be recorded on paper and saved in computer software, hard disks, and CDs, but its functions must be understood through use, testing, analysis, etc. , performance and other features.

(2) The production process of software (except copying) almost starts from scratch and goes through planning and planning, demand analysis, design, programming, testing, operation and maintenance to form a product, unlike the production of hardware. The process starts with the procurement, transportation and inventory of raw materials and components, and then proceeds through planning, design, development, production, sales, operation and maintenance to form product use.

(3) Software products are the crystallization of knowledge, and innovation has become the driving force for the development of software products and the focus of enterprise competition. Short product cycles, rapid technology updates, and high integration have become important features of software products. Therefore, compared with hardware production, software development will rely more on the business quality of developers, intellectual innovation and experience, as well as personnel organization and management, mutual communication and collaboration.

(4) So far, software production has not been able to achieve fully automatic or semi-automatic mechanized production without personnel like some hardware production, but can only be produced manually. Due to the one-sided thinking and understanding of developers, the lack of experience and technology, the psychological and physical fatigue caused by long-term development work, and the lack of mutual communication with users, various potential inherent problems arise when the software is submitted for use. Errors are unavoidable, and the number of potential inherent errors will increase as the size of the software increases. After hardware products undergo rigorous testing, testing and trial operation, errors in the design process can generally be eliminated.

(5) Compared with hardware products, the cost structure of software does not require inventory costs. Since software can be sold through the Internet, its sales cost is low. As software shifts to services, the proportion of development costs is getting lower and lower, while the proportion of usage and maintenance costs is getting higher and higher. Except for a few high-end products, most software development costs are lower than knowledge-intensive hardware products.

(6) Compared with hardware products, the market entry barriers for software products are generally lower, and the competition among software companies is very fierce. This forces software companies not to stick to traditional products, but to constantly introduce new ones and update them. Since it takes a lot of time and energy for users to learn and master a software, they generally will not easily switch to other similar software. This kind of marketing strategy that bundles users is unique to software products.

(1) High technology, high added value and high efficiency. The software industry is a typical technology-intensive and knowledge-intensive high-tech industry. The wave of national economic informatization emerging in various countries has stimulated the market demand for software; the development of multimedia technology, visualization technology, and object-oriented technology has brought vitality to software companies; the advent of the JAVA language and the development of application fields have brought new opportunities to the software industry. It has brought new market prospects, and compared with the manufacturing industry, the software industry does not require a large investment in capital and equipment, making software a "green product" with high added value and high efficiency.

(2) High correlation with other industries. As the core and soul of the information technology industry, the software industry is currently widely penetrating into the primary, secondary and tertiary industries of the national economy, transforming and upgrading traditional industries, and becoming an important foundation and support for promoting industrial structure adjustment and product technology transformation. Due to its "service" purpose, the software industry's service areas involve any sector of the national economy, especially various sectors of the high-tech industry. From information manufacturing to information services, from biotechnology, new materials to optomechanical fields, from aerospace launch, remote control and telemetry to aviation and railway dispatching and control, from telecommunications, banking, insurance, securities management to military combat command automation... …, covering almost all industrial fields and service sectors.

(3) The international characteristics are obvious. With the development of economic globalization and integration, the unification of software platforms, the opening of the software market, and the standardization of software technology have provided technical support for the internationalization of the software industry. A number of multinational companies are emerging and leading the international software market and The development of software technology standards also provides space for international software processing and business outsourcing.

(4) Specialized division of labor is becoming more and more detailed. With the development of the software industry today, those "universal" developers that can provide all types of software no longer exist. Since it is impossible for software companies to get involved in application development in all fields of the national economy and society, they have to face difficulties in the development, production, sales, and service processes. Any link in the process may provide enough space for corporate growth and competitive advantage, thus making the professional division of labor in the software industry increasingly detailed.

(5) Economies of scale are becoming increasingly apparent. The service-oriented trend of the software industry is becoming more and more clear, the industry concentration is getting higher and higher, and the economies of scale are becoming increasingly obvious. A few countries, represented by the United States, hold the core technology and intellectual property rights of software, are at the center of industrial development, and are at the high end of the value chain.

Phase Activities Planning and Requirements Analysis Outline Design Detailed Design and Coding Integration and Testing

Requirements analysis: demand investigation and analysis, demand description and modeling, demand confirmation

Requirements update

Requirements update

Requirements update

Outline design: basic architecture design, prototype conceptual model and method thinking, risk thinking, design plan formulation

Prototyping, model and algorithm design, risk analysis

Design updates

Design updates

Detailed design and programming Developers, organization and tool preparation, development planning Personnel organization, tool preparation, application design, document design Detailed design, coding and unit testing, completion of documentation

Design, coding updates

Planning and testing Test requirements, test planning, thinking Test plan drafting, test tool preparation Test plan formulation, test tool acquisition Software integration and testing

Verification and validation Verification and validation requirements, verification and validation tool preparation

Brief design review

Detailed design review

Acceptance testing and review

Concept: A branch of economics that studies economic issues and economic laws in the field of software engineering. Specifically, it studies the technical solutions, production (development) of software engineering projects proposed to achieve specific functional requirements. A systematic methodology discipline for economic analysis and demonstration, calculation and comparison of processes, products or services.

Four parts: (1) Objects, tasks, characteristics, research scope and research methods of subject research; (2) Internal components and economic activities of the software system and their correlation analysis, such as investment, cost, profit, benefit, construction period, efficiency, quality and research, development, maintenance, management activities and their correlation analysis; (3) The organizational structure, management decisions and relationship between software systems and business activities (4) The input and output of logistics, capital flow, and information flow of software systems and their impact on the outside of the system - national and regional economy, society, national defense, and people's lives.

·Task decomposition, planning, organization and coordination of software projects, as well as economic analysis and optimization.

·Analysis of factors affecting software development efficiency (labor productivity) and research on improvement strategies.

·Description of the dynamic laws of the software development process and analysis of the correlation between various economic factors.

(1) The difficulty of understanding the program;

(2) The difficulty of error correction and maintenance procedures;

(3) The difficulty of explaining the program to others;

(4) The difficulty of modifying the program according to the specified method;

(5) The degree of workload for writing programs based on design documents;

(6) The extent of resources required to execute the program.

standardization

semi-custom software

software service

classification name

Software is another part of the computer system that is interdependent with the hardware. It is a complete collection of programs, data and related documents. Among them, program refers to the sequence of instructions executed according to the pre-designed function and performance requirements; data refers to the data structure that enables the program to normally manipulate information; documents are graphic and textual materials related to program development, maintenance and use.