The use of ordinary differential equations as a shortcut technique for the description of distillation columns has been well established over the last 3 decades. Residue curve maps (RCMs) have been employed as a graphical representation tool in the analysis and interpretation of the behavior of distillation systems. However, RCMs enable one to gain insight into infinite-reflux column behavior only. This paper will be the first part of a series that looks at column profile maps (CPMs) obtained by using the difference point equation. CPMs represent the finite-reflux case, and the map depends on the values of the difference point and the net flow rate. This paper focuses on analyzing the behavior of distillation systems for ideal thermo and shows how using CPMs one can devise more creative designs. The focus of the second part lies in analyzing systems with nonideal behavior and develops tools for the synthesis of distillation.