Modelos de processamento de dados: proposta do modelo para a gestão do IVA

Abstract

The Value Added Tax (VAT) has replaced the Circulation and Consumption Taxes, which are taxes on expenditure, thus levied on the consumption of goods or services rendered, as well as on imports of goods intended for domestic consumption. As part of the implementation of VAT in Mozambique, a strategy of centralizing the processing of data relating to this tax in Maputo was chosen, in which data from the country's 26 Tax Offices (FRs) are sent through the postal services. for processing at central offices. This option was somehow a pertinent solution for the full control of VAT registration, standardization and consolidation of organizational and operational procedures, the treatment of this new and dynamic tax. However, from the perspective of implementing the VAT Management System (SGIVA) in the FRs, as a way of giving new dynamics in the treatment of taxpayer transactions, this work analyzes the hypothesis of database systems models and proposes a data processing model for VAT management. The proposal took into account the geographic dispersion of the FRs, the need to ensure effective management and the minimization of the various constraints identified in the current phase. Aspects and concepts related to the Database (DB) environment are addressed, from the fundamental characteristics of the information and its relationship with the data, the abstraction levels of the Database (internal, conceptual and external), emphasizing it. if the logical independence of the data. As these levels only deal with implementation-independent logical models, some concrete models (Hierarchical, network, relational) that the Database Management Systems (DBMS) implement and their limitations are presented. As the information (resulting from data processing) is a precious resource for an organization, aspects related to the requirements that a database management system must meet are addressed, in order to face eventualities that may jeopardize the validity of the data . Therefore, data security requirements, integrity in its handling, concurrency control and failure recovery/tolerance mechanisms are addressed. Then, a descriptive and evolutionary perspective of Database systems is drawn, starting with centralized multi-user systems, personal computers and database client/server architecture, to distributed Database systems, their implementation methods, highlighting in each of the options, its advantages and disadvantages, which made it possible to outline the proposed solution for the VAT management system. (TRADUÇÃO NOSSA)