Diplomsko delo obravnava prenovo računalniških komunikacij za potrebe izvajanja temeljnih in podpornih procesov v podjetju Grand hotel Union d.d. Prenova računalniških komunikacij ni omejena le na lokacijo, kjer je sedež podjetja in kjer se lokacijsko nahajata hotela Executive in Business, temveč zajema rešitve za integracijo dveh oddaljenih lokacij, kjer se nahajata hotela Central in Lev, v celoten sistem. Upoštevan je bil vidik razširitve nudenja storitev hotelskim in kongresnim gostom, kot tudi prenova informacijskega sistema za potrebe administracije. V diplomskem delu je prikazano dejansko stanje računalniških komunikacij v organizaciji. Na podlagi analize so podane potrebe in zahteve za integracijo novih rešitev in nato prikazane predlagane spremembe. V zaključku je podana ocena rešitve z navedenimi prednostmi in slabostmi. The diploma thesis treats the reengineering of computer communications for the supporting and fundamental business processes in the Grand hotel Union d.d. Reengineering of computer communications is not limited to the location of the headquarters where the hotels Executive and Business are located, but the integration of the solutions extends throughout the entire system and incorporates also the two remote locations, where hotels Central and Lev are situated. This thesis has taken in aspect the development of the services for hotel and conference guests, as well as the information system for the administration purposes. It also shows the actual state of computer communications in the organization. Based on the analysis and given the needs and requirements, the thesis shows the proposed changes and the integration of new solutions. In conclusion, the thesis provides an assessment of strengths and weaknesses of the proposed solutions.