# What does the author mean by "scaled version" of standard deviation?

I was trying to understand how to use XYZ analysis when I came upon this article. The author says that using coefficient of variation of an item (which is a ratio of standard deviation and average demand of the item) is flawed as it is a scaled version of standard deviation.

Textbooks have supported the use of coefficient of variation. This is so flawed that every time I read it… well, let me explain the issues. The coefficient of variation is a scaled version of the standard deviation of the historical sales. This tells us nothing about the easiness to forecast sales or not.

^ extract from the article

I wanted to know -

1. What is meant by the statement in bold from the passage?
2. And, if you would entertain it, under what conditions scaled measures are flawed?

$$c_v = \frac{\sigma}{\mu}$$
so it calculates the variability $\sigma$ relatively to the mean $\mu$. But beware that there are problems with this statistic, as described in both links.