CodB includes ALL the cost of running the business (materials,...

CodB includes ALL the cost of running the business (materials, wages, depreciation, advertising etc.).

Not conventionally, it doesn't.

Materials and wages relating directly to the production of goods or provision of services falls under Cost of Goods Sold (CoGS) (or Cost to Prove Service). (From this Gross Profit, hence Gross Profit Margin is derived).
Generally, CoGS are considered to be variable in nature (i.e., the more widgets ARB produces, the more materials it will need to buy, and vice versa).

But Cost of Doing Business represents the costs than need to be incurred anyway, irrespective of the level of business activity. Examples of this include executive salaries and other wages, as well as cost of other corporate overheads, eg. HR, Accounting, IT, Marketing, etc, as well as leases and depreciation. These sorts of expenses are quite fixed, no matter how many winches and bull bars ARB makes.

In this latest ARB result, the GP Margin went up a lot (usually a sign of pricing power, whereby a company is more than able to pass on increases in cost of materials and other expenses.) On the other hand this excess margin was invested in CoDB, which should not normally be the case, because CoDB is generally, as I said, fixed on nature.

So why is CoDB rising? Ordinarily, it might reflect poor cost control and hence, not be a good thing. But the judgment call I make in ARB's case is that it reflects an investment in additional capability for growing the business, i.e., "infrastructure" costs being incurred now, to support higher levels of future Revenue.

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