Use case Analysis Technology read Note two

dividing large systems:

If it is a large system, then it is very important to divide the large system into small systems. Select the most important part of the system first. The main architectures are as follows:

an MVC structure, a layer used to show, a layer for control, a layer for data storage. For example, jsp,struct is the architecture.

second, Pipeline and filter system structure. The main idea is that a part of the input data, processing the data, and then output, the next part of receiving, processing, and so on, such as Freeradius,Jradius is this architecture.

Thirdly, the object-oriented architecture pattern. The system is defined according to the data and is associated with various functions. The use case validation architecture can be used, and each subsystem should have:

--- a single function

--- strong polymerization --- each of its parts has a strong correlation with each other

---- Loose coupling --- the completion of its work is less dependent on other subsystems

There is no significant communication between ---- and the minimum communication ---- subsystem of other subsystems.

The operations in the interface are from the time series diagram. Each subsystem is considered as a whole system, and each system has performers and use cases. Constantly divide the large system into small systems, when the system is small enough, there is no need for more division there is enough detail to achieve.

Topic Summary: A topic summary refers to what we use or work with in use cases. is to create a basic element of the system, which is a way to describe the domain. A simple way to find a topic summary is to find the entity or data used. By using the time series diagram to draw the scene, the system object can be replaced by the topic summary, the subsystem is also replaced by a system summary, so that the message sent to the subsystem is sent to the topic summary and performer information, and most importantly to determine the behavior of the topic Summary, determine the topic summary and their behavior, the design of the class lay the foundation.

through the time series diagram, we find the topic summary, we can find the summary must make the corresponding message, and then the message to participate in the use case class, participate in Class View is to tell us what classes to develop.

The use case tries to show the workflow in the system and is the basis of the black box test and User Guide.

The Subsystem view shows the subsystems that make up the system and is the basis of system reuse and maintenance.

The use Case view is a presentation of the system's appearance, and only the system view shows the subsystems that make up the system, one from the customer perspective and one from the development perspective.

Usually the first iteration deals with the highest risk, and the second iteration deals with the secondary risk.

Using use cases to estimate work:

1. Performer Weighting

2 . use case weighting:

The concept of a transaction here is a path, including an optional path, which is a set of atomic operations.

An unadjusted use case point (UUCP) is obtained by adding the weighted total of the use case to the weighted total of the performer.

3. Technical factor weighting: Calculate the complexity of the project technology, can take advantage of the technical complexity factor. The rank of each factor is determined from 0 to 5 . 0 rank means that this factor is not related to the project, and5 represents it as the most important. Then use the factor to multiply the weights of each factor and add them.

4. the Group's environmental factors and weights . The rank of each factor is determined from 0 to 5 . 0 rank means that this factor is not related to the project, and5 represents it as the most important.

ef=1.4+ ( -0.01*efactor) efactor= All (weight * rank) plus and

Final Compute use point (UCP)

UCP=UUCP * TCF * EF

then make a project estimate to see how many of F1-f6 are below 3, F7-f8 have a few higher than 3, and then add these two numbers together equals N

Use case Analysis Technology read Note two