The final graph we shall look at in this section is the ogive. This is a way of plotting the cumulative frequency of occurrences. The cumulative frequency is like a running total of all events as they occur, and it is often found on a tally chart.

Let's look at an example.

Problem Frequency Cumulative Frequency
Colour ran at first wearing 2 2
Don't like them 2 4
Heel fell off 7 11
Lining disintegrated 8 19
Odd sizes in a box 4 23
Too tight 3 26
Trim fell off 12 38
Wrong colour for outfit 3 41

This information can be represented graphically by means of an ogive (an architectural term for the rib of a vault). Pareto charts, as you will see in the next section, are often completed by adding an ogive showing either the cumulative frequency or the cumulative percentage for the defect categories.