How to Use the CRC model to determine requirements

Author:♀Chen xiao'er♂Go to 51cmm. com

CRC (Class-Responsibility-collaborator) card modeling is a simple and effective object-oriented analysis technology. In an OO (Object-Oriented) Development Project, including users, system analysts, and developers, CRC card modeling is often applied during modeling and design, so that the entire development team has a general understanding of consistency. It consists of three parts: 1. Class) 2. Responsibility) 3. Collaborator) A class represents many similar objects. Objects are things of interest in system modeling. They can be a person, place, thing, or any concept that is important to the system. The class name is usually listed on the top of the CRC card. The responsibility is anything that the class needs to know or do. These responsibilities are the knowledge of the class itself, or the knowledge required by the class during execution. Collaboration refers to other classes that get messages or assist in the execution of activities. In a specific scenario, perform one (or more) step with the specified class as one assumption. The Cooperative Classes are arranged along the right side of the CRC card. The CRC model is a collection of CRC cards. It represents all or part of an application domain or problem domain. The CRC model is the most common user. The whitepaper address is used to collect and define user requirements for an object-oriented application. The figure shows an example of a CRC model for a shipping/inventory control system. The CRC card displayed will be placed on a desk or work desk. Note Card placement: cards that work together are close to each other. Unrelated cards cannot be placed nearby. Let's talk about how to create a CRC model? There are six steps: 1. Join the CRC model group (the model group includes related customer field personnel, designers, recorders, and system analysts ). 2. Arrange the model room. 3. Free collective discussion The content is based on the system objectives of this CRC model. For example, who developed the system? What kind of support does business need from this system? What information does it need at work ?...... In short, we should try our best to achieve the goals that meet system requirements, including the requirements for resources, conditions, activities and personnel during activities. 4. Explain the CRC Model Technology (after completing the collective discussion, the designer will describe the CRC model process. It usually takes 10 to 15 minutes. This process involves creating several CRC card examples for reference ). 5. Repeat the CRC model steps. 6. Execution case scenario test User scenario testing is a task process model in which users will actively participate to ensure that the requirements are accurate. The basic idea is that a group of business experts (that is, the customer side), designers, and system analysts step by step through a series of use cases to confirm that the CRC model can accurately reflect user needs. To be honest, the CRC model is a communication method, how can customers and developers establish a system requirement that can describe accurately and reach consensus through this effective, easy-to-implement, and easy-to-operate method. CRC modeling because users are actively involved in the definition of the model, their satisfaction with the work will increase, and with developers to create this CRC model, through this series of model cards, both parties reach a consensus on the system requirements. Of course, the CRC model also has some disadvantages. The CRC model is only a part of the definition of user requirements for Object-Oriented applications. You should also consider use cases, prototypes, and formal requirement documents. Whether CRC modeling is required depends on the project, enterprise, and customer's own existence and required conditions.