8.12. Modern methods and tools for developing application software

The concept of “modular design” is closely related to the implementation of the top-down design method. The sequence of logically interconnected fragments designed as a separate part of the program is called a module. The following properties of software modules are distinguished:

• reference to the module can be by name, including from other modules;

• at the end of the work, the module must return control to the module that caused it;

• the module must have one input and output;

• the module must have a small size, ensuring its visibility.

In the development of complex programs, the head control module and its subordinate modules are separated, providing the implementation of individual control functions, functional processing, and auxiliary modules that guarantee package service.

The modular principle of program development has a number of advantages:

1) a capacious program can be developed simultaneously by several performers, thus reducing the time frame for its development;

2) it is possible to create a library of the most commonly used programs and use them;

3) if segmentation is necessary, the procedure for loading large programs into the OP becomes much easier;

4) there are many natural control points, designed to monitor the development of programs and monitor the execution of programs;

5) effective testing of programs is provided, design and subsequent debugging take place much easier.

Structural programming is used to facilitate the process of developing and debugging software modules, as well as the process of their subsequent maintenance and modification.

The development of software tools for programming economic tasks is based on programming automation systems, or programming systems that provide the ability to solve many problems directly in a computer operating system environment.

The tasks of economic management have a number of features that distinguish them from other types of tasks:

1) the dominance of tasks with relatively simple computational algorithms and the need to form cumulative totals;

2) work with large arrays of initial information;

3) the requirement to provide the majority of information in the form of documents in tabular form.

CASE technology is a combination of system analysis tools, design, development and maintenance of complex software systems and allows developers to use extensive capabilities for various kinds of modeling. The coherence of the interaction of all professionals involved in software development, guarantees a centralized storage of all necessary information for the design and monitoring data integrity.

The ISDOS project consists of modules that provide:

• input, control and coding of specifications of the designed system;

• analysis of the correct formulation of tasks and their consistency;

• identification of errors and the issuance of messages to users, as well as the elimination of duplication in the original information;

• conversion of problem statements after checking the source data into machine programs;

• highlighting the main elements of the information system.

The listed modules are interconnected. At the same time, their separation is rather conditional.