The purpose of this thesis is to clarify the reasons and consequences of failed implementations and poor adoption of CRM / SFA tools in sales teams, that have been recorded in recent years. Almost 70% of initiatives to introduce new technologies for sales teams have failed in the return on investments. The goal of the thesis is to create requirements for a new CRM / SFA, which will support salesmen and sales teams in a better way. It describes the way the sales team work, it describes business cases and determinates its key activities. Using perceived usefulness, I create a set of system requirements for CRM / SFA tool, which will support salesmen and improve their sales performance.