Effective company management, the use of new and modern methods and techniques of management, require the right quality data that can be provided by integrated information systems. Therefore, the bigger number of small and medium-size companies have decided to introduce this tools although they have recognized that the introduction process is difficult and expensive. However, the alternative solution cannot be easily found. The article presents results of pre-implementation operation. This operation has been realized according to the developed methodology which includes the following steps: the analysis of needs and the working conditions of a company, the structure of a model of a production process (in a company) supported by an integrated computer system; the choice of information system’s supplier; the implementation work scheduling. Special attention was paid to main aspects of pre-implementation operation and effect of successive steps.