There are many ways to outline design. In the early days, there were modular methods and functional decomposition methods; in the late 1960s, data flow-oriented and data structure-oriented design methods were proposed; in recent years, object-oriented design methods were also proposed.
The format of the outline design is as follows:
1.1 Purpose of writing
1.4 Reference Materials
2.1 Requirements Regulation
2.2 Operating Environment
2.3 Basic Design Concept and processing flow
2.4 system architecture
2.5 the relationship between functional requirements and programs
2.6 manual processing
2.7 unresolved Question
3 Interface Design
3.1 User Interface
3.2 External Interface
3.3 Internal Interface
4 Operation Design
4.1 Operation module combination
4.2 Operation control
4.3 Operation time
5 System data structure design
5.1 Essentials of logical structure design
5.2 Essentials of physical structure design
5.3 Relationship between data structure and program
6 System error handling design
6.1 Error message
6.2 Remedial measures
6.3 System maintenance design
Purpose of writing
Describe the purpose of writing this brief design specification , Point out the intended readers.
a. The name of the software system to be developed;
b. List the task proposer of this project , Developers, users, and computing stations (centers) that will run the software.
List the definitions of the specific terms used in this document and the original phrases of the foreign initials.
List relevant reference documents, such as:
a. The approved plan or contract of this project, and the approval of the higher authority ;
b. Other published documents belonging to this project;
c. Documents and materials cited throughout this document, including the software development standards to be used. List the titles, document numbers, publication dates and publishing units of these documents, and explain the sources from which these documents can be obtained.
Describe the main input and output items and the functional performance requirements of the system.
Briefly explain the requirements of the operating environment (including hardware environment and support environment) of the system.
Concept and processing flow
Describe the basic design concept and processing flow of this system, try to use the form of diagrams.
The basic concepts of programming include programs, data, subroutines, subroutines, co-routines, modules, and sequence, concurrency, parallelism, and distribution.
Describe the hierarchical structure of the system, call relationships, and specific implementation technology types.
Describe the manual process (if any) that has to be included in the working process of this software system.
Describe the issues that have not been resolved in the outline design process but the designer believes that they must be resolved before the system is completed.
Describe the commands and their grammatical structure that will be provided to the user, as well as the answer information of the software.
Describe the arrangement of all interfaces between this system and the outside world, including the interface between software and hardware, and the interface relationship between this system and various supporting software.
Describe the arrangement of interfaces between various system elements within this system.
Operation module combination
Describe the various operation module combinations caused by different external operation control of the system, explain each Run the internal modules and supporting software experienced.
Describe the methods and operation steps of each external operation control.
Describe the time that each combination of running modules will occupy various resources.
Give the name, identifier and each data item of each data structure used in this system The identification, definition, length of records, files and departments, and their hierarchical or tabular relationship.
The main points of the physical structure
The storage requirements of each data item in each data structure used in this system, the access method, the access unit, and the physical access Relations (index, equipment, storage area), design considerations and confidentiality conditions.
Relationship with program
Describe each data structure and the form of accessing these data structures:
Use a list to explain the form, meaning and processing method of the system output information when each possible error or failure situation occurs.
Describe the possible workarounds after the fault occurs, including:
a. Back-up technical description The back-up technology to be adopted, when the original system data In case of loss, the technology of creating and starting the copy, such as periodically recording disk information to tape, is a backup technology for disk media;
b. The technical description of the reduction in efficiency is ready to be adopted The back-up technology of using another less efficient system or method to obtain certain parts of the required results, for example, the efficiency reduction technology of an automatic system can be manual operation and manual recording of data;
c. The recovery and restart technology describes the recovery and restart technology to be used to enable the software to resume execution from the point of failure or to restart the software from the beginning.
System Maintenance Design
Describe the arrangements made in the internal design of the program for the convenience of system maintenance, including the special arrangements in the program for system inspection and maintenance inspection points and Dedicated module. The corresponding relationship between the various programs can be in the form of the following matrix diagram;
(1) Hierarchical diagram. Hierarchical diagrams are used to depict the hierarchical structure of software. A rectangular box represents a module, and the lines between the boxes represent the calling relationship. As shown in the figure, the top box represents the main control module of the text processing system, which calls the lower modules to complete all the functions of text processing. Each module of the second layer completes a main function of text processing.
(2) HIPO diagram. HIPO diagram is a "hierarchical diagram plus input/processing/output diagram" invented by IBM. The hierarchical graph plus the number is called the H graph. On the basis of the hierarchical diagram, except for the topmost box, each box is numbered. Each box in the hierarchy diagram has a corresponding IPO diagram (representing the processing process of the module). The number that should be added to each IPO chart is consistent with the number of the (corresponding) hierarchical chart it represents. IPO diagram is short for input/processing/output diagram.
(3) Structure diagram. The structure diagram is a tool for software structure design proposed by Yordon. The structure diagram is similar to the hierarchical diagram. A box represents a module, and the name or main function of the module is indicated in the box. The straight line (arrow) between the boxes represents the calling relationship of the modules. Use annotated arrows to indicate the information passed back and forth during the module call. The tail is hollow, indicating that the data is passed, and the solid indicates that the transmission is control.