SAP SD - IMPLEMENTATION OF AN ERP SYSTEM - ANALYSIS AND RECOMMENDATIONS IN THE IT UNIT TESTING PHASE. A CASE STUDY (II). - VIOREL-COSTIN, BANȚA (Annals of 'Constantin Brancusi' University of Targu-Jiu. Economy Series / Analele Universităţii 'Constantin Brâncuşi' din Târgu-Jiu Seria Economie, 2019)