How Do I Write a Design Mission Statement?

The detailed design specification can also be called program design specification. The purpose of compilation is to explain the design considerations of each program (each module or subroutine) at each level of a software system. If a software system is relatively simple and has few levels, this document may not be written separately. The relevant content is incorporated into the outline design Manual.

Detailed design specification

The detailed design specification can also be called program design specification. The purpose of preparation is to explain the design considerations of each program (each module or subroutine) at each level of a software system.

The content requirements for detailed design specifications are as follows:

1 Introduction

1.1 Purpose of writing

1.2 Background

1.3 Definition

1.4 References

2 Organizational structure of the program system

3 procedures (

1 Introduction

1.1 Purpose of writing

Explain the purpose of this detailed design specification and indicate the intended audience.

1.2 Background

a. The name of the software system to be developed;

b. The project proposer, developer, user and computing center running the program system.

1.3 Definition

List the definitions of specialized terms used in this project and the original phrases of the acronyms in foreign languages.

1.4 References

List relevant references, such as:

a. Approved plan assignments or contracts for this project, and approvals from higher authorities;

b. Other published documents belonging to this project;

c. Documents cited throughout this document, including software development standards to be used. List the titles, file numbers, publication dates, and publishing units of these documents, and indicate the sources from which they can be obtained.

Structure of 2 program system

Use a series of charts to list the names, identifiers, and hierarchical relationships between each program (including each module and subroutine) within the program system.

3 program 1 (identifier) design instructions

Starting from this chapter, design considerations for each program at each level are given individually. The outline given below is for general cases. For a specific module, especially a lower-level module or subroutine, the content of many entries is often the same as that of the corresponding entry of the module on the upper level to which it belongs. In this case, simply explain this Just one point.

3.1 program description

Give a brief description of the program, mainly explain the purpose of the design of the program, and also explain the characteristics of the program (such as resident memory or non-resident? Is it a subroutine? Reentrant or non-reentrant Is there a coverage requirement? Is it sequential or concurrent? (...)

3.2 Function

Explain the functions that the program should have, which can be in the form of an IPO chart (that is, an input-processing-output chart).

3.3 Performance

Explain all performance requirements for the program, including requirements for accuracy, flexibility, and time characteristics.

3.4 entries

Give the characteristics of each input item, including name, identification, data type and format, valid range of data value, and input method. Quantity and frequency, input media, source of input data, security conditions, etc.

3.5 output items

Give the characteristics of each output item, including the name, logo, type and format of the data, the valid range of the data value, the form, quantity and frequency of the output, the output medium, the description of the output graphics and symbols, and security conditions and many more.

3.6 Algorithm

Explain in detail the algorithm used in this program, specific calculation formulas and calculation steps.

3.7 process logic

Charts (such as flowcharts, decision tables, etc.) supplemented with the necessary instructions to represent the logic flow of the program.

3.8 Interface

Use the form of a diagram to explain the upper layer module to which this program belongs, and the next layer modules and subroutines to this program, explain parameter assignment and calling methods, and explain the data structure (database, data volume).

3.9 Storage allocation

If necessary, explain the storage allocation of this program.

3.10 Annotation Design

Program Notes

a. Notes added at the beginning of the module;

b. Notes at the branch points;

c. Comments on the function, scope, default conditions, etc. of each variable;

d. Comments on the logic used, etc.

3.11 Detailed Design Specification 3.11 Restrictions

Explain the restrictions encountered during the operation of this program.

312 Detailed Design Specification 3.12 Test Plan

Explain the plan for unit testing of this program, including the technical requirements for testing, input data, expected results, schedules, personnel duties, equipment condition drivers, and stub modules.

3.13 Detailed Design Specification 3.13 Unresolved Issues

Explain the problems that have not been resolved in the design of this program and that the designer believes should be resolved before the software is completed.