The box structure (2) of the net chamber specification and design is not allowed, it is strictly forbidden to reprint this column This paper is reproduced from the software engineering expert network www.21cmm.com. Do not reprint without CBS license, thank you for your cooperation 4, box The structural hierarchy is as described earlier, and the hierarchical hierarchy has evolved with stepwise and verification. This is a hierarchical structure used instead of a partial structure, that is, each use of a box has different locations in a hierarchical structure, and all defined by the order of the box and concurrent use Processing process. Of course, the hierarchical structure used does not mean that the code must be replicated anywhere in use. The example below depicts an initial black box to be detained into a state box, and then refine into a bright box. The control structure of the bright box contains six black boxes in the next level. These black boxes may be the same or different, or several combinations. The hierarchical structure using system components helps to maintain intelligent control over system development management. 5. The principle of box structure This section summarizes the four important principles of the box structure guide and analysis (Mills.Linger.hevner1986, 1987). The first two principles for the box structure refine process, and the latter two are for the design process. Reference Transparential Transparency: During the authorization development of a system component, all the needs of the component should be completely clarified, so that the component logically no longer needs further specifications. Each black box should define all of the external behavior required for the system or its component. The reference transparency must also be met when the status box needs to perform the behavior of the black box and the required behavior required to perform the status box correctly. These three boxes define behavior, status, and processes, but they are complete and defined with the system and system components in behavior, and will not miss any behavior. This hierarchical structure with reference transparency can delay detail implementation without missing details. The bright box has a key role in maintaining the reference transparency. Because it organizes and connects to the subsystems and components to be embedded in the next layer. Effective project management requires a large number of details to be used for proxy and development. The reference transparency in the box structure provides a concise agent and responsibility. When the component is assigned to the development team at a certain trust, the component commitment is identified and the responsibility is given. In addition, reference transparency is clear, reducing many discussion and coordination, thereby simplifying communication between project members, and improving efficiency. Transaction Closure Principle: The system or its components must be sufficient to obtain and retain all status data. At the same time, status data must be sufficient to complete all transactions. The transaction is a high level of behavior, which can be composed of low-level transactions. For example, the transaction "Bank Account List" can be composed of "access report", "deposit", "withdrawal". Transaction closure defines an iterative analysis process to ensure that transactions and status data in the specifications of the system or their components are sufficient. This process begins with the main transactions made by major users, and the defined status data should support these transactions. These data require additional transactions to initialize and update them, which will generate more status data, and so on. This iteration has not been needed to increase the data until you need to increase the data. State Migration Principle: System Data should be migrated and packaged to the best and small system part, so don't copy update. Status migration makes status data into a suitable level to reduce the complexity of system specifications and structures. For example, a bright box containing a state data T and a black box will be called in the next layer. If T is referenced in the status box of that black box, then t can migrate and package down without having to copy update.
