Requirement analysis of software engineering---

Demand analysis is the last phase of a software-defined period, and its basic task is to accurately answer "what the system must do." ”

A simple summary of demand analysis with mind mapping

1, in the Structured analysis method, "Data dictionary" is the core of modeling, there are three modeling methods, each of which should have a corresponding tool to describe

(1), data model, with entity-Contact diagram description;
(2), functional model, with a flow chart description;
(3), behavior model, described by state transition diagram.

2, in the structured analysis method, the data flow diagram and the database dictionary compose the logical model of the system together. There is no data dictionary, data flow diagram is not strict, but there is no flow chart, the dictionary is difficult to play a role. Only the data flow diagram and the precise definition of each element in the streaming diagram can be combined to form the specification of the system.

3. It is also important to note that before the end of the requirements analysis phase, the system analyst should write the software

Requirements specification, in written form to accurately describe the software requirements.

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First of all, for software engineering, the development of software engineering standards has a life cycle, from initiating recommendations to releasing and maintaining as follows:

In the process of development, according to this circular life cycle will be circulated several times, constantly modified and corrected, become mature gradually. Before the software development, there is a very important task, is to write software documents, software documents from the formal perspective, broadly divided into two categories: one is the work table, is the development process filled in the various forms; The second category is the preparation of technical information or management technical information. If you divide from the production and use of documents into three categories:

Write a good software document, a good document is equivalent to a beautiful introduction or user manual, so that the relevant staff to fully understand the new software, so as to make better software.

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There are several more important documents in the software documentation that highlight

1. Software Requirement Specification

Software requirements are mainly from the separation of functions from the reality, describing the software to "do what", in the software requirements, the main functions and links are as follows:

2. Summary design instructions and detailed design instructions

The summary design and the detailed design all belong to the software design, is according to the software requirement explanation to export the system realization Plan, mainly describes "how to do".

Outline design Specification--Design the main module of composing software and its relation;

Detailed design instructions-design the implementation of the module algorithm and data structure.

The most important part of the outline design document is the hierarchical data flow diagram, the structure diagram, the dictionary and the corresponding text description, etc. the most important part of the detailed design document is the flowchart of the module, the state diagram, the local variables and the corresponding text description. A module for a detailed design document. The outline design specification is equivalent to the assembly drawing in the mechanical design, and the detailed design specification is equivalent to the part drawing in the mechanical design.

3. Database Design Manual

Everyone is familiar with the life cycle of software engineering, and the database has its life cycle:

The database is the foundation of the building. Before we do the computer room charge system, the late output error data, data type errors and other pre-database design has a close relationship, if in the new design database or optimization, it will take a lot of time, the database is the foundation of the whole software, there is no solid foundation, software is at stake. Therefore, the database design specification is the most serious in the software development process. 4. Operation Manual

The Operation manual mainly introduces how to install and initialize new software for new users, how to use the installed software properly, and how to solve some minor errors in the process of using. The basic operating manual is important for new users, which is also a very important document.

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Software engineering video has been recently read, most of the content has been used to summarize the mind map, and now the general introduction of software engineering

Software Engineering is a description specification. Understand and master the software Development steps, methods, and guidelines to

Overcoming and solving "software crisis";

Improved "Software production" methods, tools

Increase the productivity of your software

First of all, from a large aspect, software engineering has two major components of management and development technology

1, first said management

With the progress of the times, the scale of software will continue to increase, developers will gradually increase, development time will become more and more long, which will increase the difficulty of project management, in the software development process, the consequences of management errors more serious than the consequences of procedural errors; So, software engineering management is really important.

2, besides the development of technology

Software Engineering has three goals, quality, cost, schedule, these problems can be solved by the technology

A team, make an excellent software, need not only the development of technology, if a team, not a good management, like disunity, each of the road, each of the things, then the team will never write excellent software, so say, can do a project, good management, good development technology is indispensable.