Incremental calculus is a powerful and flexible tool for the analysis of system behaviour, dependent on variables which are subject to discrete changes. This is of particular interest when attention is focused on the relative changes that take place, namely on the ratio of an increment of a variable (or a function) to its original value prior to the change. Such circumstances are common in the business world, and this is why incremental calculus can be widely applied for managerial purposes, both for diagnosing past events and for planning and decision making. The basic operational rules of incremental calculus are introduced, and their use is demonstrated by several examples. Although the examples concentrate on problems of concern to managers and business analysts, the methodology described in this paper can be easily applied in many fields of science and technology.
