Requirement Analysis and System Design 2

Continue reading. During this period, I have read four to six chapters of demand analysis and system design. I have a better understanding of this central idea, I have a certain understanding of the author's thinking about the demand analysis stage in software development. The author has his own opinions on the methods of demand analysis and solutions to problems, and these ideas have helped me a lot.

The fourth chapter describes the requirement specification. In this chapter, the author proposes to describe the requirements using graphs and other formal models. The Requirement Specification Description uses the customer's narrative requirement as the input, and the Construction Specification Description Model as the output. These models are divided 3 Group, namely, the state model, behavior model, and state change model. The state of an object is determined by its attributes and associated values. The state specification provides a static view of the system. Generally, you must first identify the class by using the noun phrase method, common Mode methods, case-driven methods, CRC Methods and hybrid methods, followed by association modeling, followed by discovery Association, indicating association, followed by aggregation and combination link modeling, followed by generalized link modeling, Object Modeling, their modeling methods are the same as their associations. The behavior Specification Description describes functions from the operational perspective. It is a use case for requirement analysis and system design, including case modeling, activity modeling, interaction and public interface modeling. However, State change modeling refers to object state modeling, which describes the function from a dynamic perspective, and state diagrams are used to model state changes. In chapter 5, from analysis to design, I first learned about advanced class modeling, including constructor, constraint, export information, visibility, quantitative Association, Association class, and parameterization class. Structural expansion of existing UML Modeling element, which changes the definition of an existing element. A special constructor that solves the design model problem is called a profile. Any modeling element can have an associated constraint, or it can be constructor. The annotation symbol can contain the body to indicate the constraint. It can contain any information. To ensure that the annotation is a constraint, it should use keywords. <Constraint> The exported information is a constraint on one attribute or one association. The exported information is obtained from other model elements, and attributes can be exported and associated; an association class is also called a class association. An association class is usually used when there is a many-to-many association between two classes and each associated instance has its own attribute value, it has an implicit constraint. It cannot have a copy associated with the associated object. However, a specific class is independent of the associated class, the main code of a specific class does not need to specify the attributes of the relevant class. The hierarchy reduces complexity from the exponential to the polynomial. It introduces the object hierarchy and the communication between the existing layer and the layer. The solution to complexity control depends on how classes are combined into the class hierarchy, this simplifies the network structure. In this way, classes can form layers to emphasize the layer decomposition between layers and allow network interactions within the layer; the package is used to divide the logic model of an application, represented by a collapsed icon. Boundary-control-entity is a class-based three-factor Object Modeling method. There are three important relationships in the class: Association, aggregation and generalization. Aggregation is divided 4 Type: Exclusiveowns Aggregation, Owns Aggregation, Has Aggregation and Member Aggregation, aggregation, and proxy are an important substitute for modeling for generalization and inheritance. Chapter 6 describes architecture and program design. In iterative and incremental software development, the analysis model is continuously refined using technical details. Once the technical details consider the software / Hardware, the analysis model becomes the design model. System design involves two main problems: System Architecture Design and detailed program design in the system. System design describes the system from the perspective of system modules, including determining the solution policies for the system's client components and server components. Architecture Definition classes and packages are organized hierarchically, processes are allocated to computing facilities, reuse and construction management, and architecture design solves problems related to multi-layer physical architecture and multi-layer logical architecture. The description of the internal work of each module is called the detailed design. The detailed design develops a complete algorithm and data structure for each module. These algorithms and data structures are specifically designed for all the constraints on the underlying implementation platform. The collaboration model is designed in detail. The collaboration model is required to implement program functions captured from the use case.

The reading at this stage gave me a deeper understanding of the demand analysis. Through the study of this book, I found that the ideas in this book have inspired me a lot, let me know that the problem can be solved better and faster through plotting or other methods during requirement analysis, and the requirement report can be obtained and analyzed more clearly, it is of great help to software development.

Requirement Analysis and System Design 2