In this study, definitions and explanations of the relationships between selected independent and dependent parameters of roller electrospinning are introduced. We aimed to define and completely analyze new parameters, such as the number of Taylor cones per square meter, the spinning performance for one Taylor cone, total spinning performance, fiber diameter uniformity coefficient and non-fibrous area percentage. Also, new measurement methods were developed and explained to analyze these parameters. According to the experimental results, strong and significant relationships between independent and dependent parameters of roller electrospinning were found. These independent and dependent parameters were affected by varying the concentrations of polyurethane and tetraethylammoniumbromide (TEAB) salt. In particular, the spinnability of the polymer solution, which is the most important factor for the roller electrospinning method, significantly increased with the TEAB concentration. If the spinning performance is positive, a specific solution is spinnable. However, the solution is not spinnable if the spinning performance is zero.