Conceptual Model -- Analysis Model learning notes

The following content is from: Analysis Mode.

There are many differences between analysis and design. The purpose of design is to achieve a higher technical solution, and the purpose of analysis is to understand the nature of the problem. This is not just a simple task of listing requirements using use cases.

Suppose we want to develop a snooker billiards simulation game. after hitting the white ball, the white ball follows a certain trajectory and hits the red ball. Use Cases can list tens of thousands, but this is not enough for us to develop a better software-you must understand the laws behind the movement. This problem is not difficult to solve because these rules are well known.

However, in many application fields, the relevant rules are not easy to understand. To this end, we have created a conceptual model-an intellectual model that runs our knowledge and simplifies the problem. It can be understood as the law of motion. When expressing the law of motion, it ignores many other factors, such as the influence of wind power and friction. This process is actuallyGet simple models from a complex world, and then guide the complex world with simple models..

There may be multiple models, as in the above example, the Newton model or the Einstein model can be used. You may feel that the Einstein model is more accurate, but more complex. Because the ball speed is slow, you can ignore the changes in quality. This indicates a problem:There is no correct or wrong model, and there is only a model that is more suitable for the current task.

Modeling principles: There are no right or wrong models, but good or bad models.

The choice of model will ultimately affect the flexibility and reusability of the system. You may think that using the Einstein model may be more flexible and can handle atomic collisions. However, a snooker simulation game is unlikely to use atomic collisions. Excessive consideration of flexibility will be overly complicated software systems. To build a software system that meets a specific purpose, you must develop a model that meets the actual needs. What you need is the simplest model that can be obtained.

A simple model is not necessarily an instant model.The birth process of a simple model involves a process from simple to complex, from complex to simple.. At the beginning, we often see the demand demonstration. With the in-depth analysis, we will find all aspects of the system, including implicit functional and performance requirements and restrictions, this is an increasingly complex model. In depth, arrange all aspects of the system according to certain principles, and finally find a simple model.

The expression of the conceptual model. AvailableProgramming LanguageThe advantage is that it can be quickly verified and reduce the workload from model to idea. The disadvantage is that the modeling process may fall into a language usage problem and ignore the actual problem. It may also use the unique features of the language to increase the difficulty of converting the model to other languages.

To avoid these problems, use analysis and design techniques. It can help people focus on conceptual issues rather than software design issues.

One advantage of using Analysis and Design Technologies is to involve domain experts in Conceptual modeling. What is a field expert? LHS, hxy, and lxr should have certain roles.Effective models can only be created by employees who know the field, rather than by software developers.. (? I have always had a question: what is a conceptual model? What is the difference between it and architecture? The conceptual model should be the essence of the problem, just like the law of motion. Architecture is a realistic solution after understanding the essence .)

Expert knowledge is the key to establishing a good analysis model.

The author strives to make the analysis technology independent from the software technology. Ideally, the Concept Modeling Technology is independent from the software technology, just like the law of motion. However, this may not be the case. Our current modeling generally relies on object-oriented technology.

The conceptual model should be closer to the software interface, rather than the software implementation.

Modeling principle: a conceptual model is associated with an interface (type) rather than an implementation (class.

After learning this section, the analysis model and conceptual model are a brand new field for me. I have written so many notes for learning in this section. Summary:

1. The purpose of analysis is to obtain the essence of the problem. The final structure is the conceptual model.

2. The purpose of the design is to solve the problem and the result is the architecture design or solution design.