Software Engineering Review materials (3)

Content summary

1. What is a demand project?
2. What is Software Requirement Engineering?
3. Importance of software requirements
4. Difficulties in software requirements
5. software requirements
6. Activities of the demand Project

Requirements:
(1) recognition: the activities of the demand project, the specific tasks in the traditional demand analysis stage, and the demand analysis methods.
(2) Understanding: data flow chart, state chart related concepts and description methods, etc.
(3) Integrated Application: it can analyze the demand of an application system with a moderate scale using a structured analysis method and provide a data flow diagram.

1. What is a demand project?

Concept of demand Engineering (re)
It is a discipline that uses proven technologies and methods to analyze requirements, determine customer needs, help analysts understand problems, and define all external characteristics of the target system.

Requirements Engineering RE can be divided:
System Requirement Engineering (for an entire system composed of software and hardware)
Software Requirement Engineering (if only for pure software ).

 

2. What is Software Requirement Engineering?

Software requirements: users' expectations for the target software system in terms of functions, behaviors, performance, and design constraints.
Software Requirement Engineering is a discipline that analyzes and records software requirements. It divides system requirements into major subsystems and tasks and assigns these subsystems or tasks to the software, the system requirements are converted into software requirement descriptions and performance parameters through a series of repeated analysis, design, comparative research, and prototype development processes.

3. Importance of software requirements

Importance of requirements
Frederick Brooks in his 1987 classicArticle"No silver bullet" describes the importance of the requirement:

The most difficult part of developing a software system is to accurately describe what to develop. The most difficult conceptual work is to compile detailed requirements, including all interfaces for users, machines, and other software systems. If this task is wrong, it will cause great damage to the system, and it will be extremely difficult to modify it in the future.

4. Difficulties in software requirements

Software requirements are one of the most complex processes in software engineering:
Its implementation is undoubtedly closely related to the characteristics of various application industries.
The lack of non-functional requirement modeling technology and its relationships with functional requirements greatly increase the complexity of the demand project.
The difficulties in communication have made it difficult to implement the demand project because the system analyst, demand analyst, and other personnel have different points of view and different knowledge backgrounds.

6. Activities of the demand Project

The activities in the requirement project can be divided into two categories: requirement development and requirement management.

Common Requirements Analysis Methods:

Function Decomposition Method
Data Stream-oriented structured analysis method (SA)
Data Structure-oriented analysis methods
Information Modeling Method
Object-Oriented Analysis Method (OOA)

Requirement Project Summary

Software Requirement Engineering is a process in which software developers work closely with users to fully exchange opinions and obtain consensus on requirements.
On the developer side, the main role involved in the work is system analysts and System Engineers. They are responsible for communicating the understanding and opinions of users and developers and playing a bridge role.
The final task of the demand engineering stage is to complete the Requirement Specification Description of the target system, determine the system's functional, non-functional requirements and performance, and lay the foundation for subsequent development.
The SA, prototype, and OOA methods are commonly used in this phase.