Originally posted by Kunzite I guess we need monochrome to explain what an impairment test is
Let me try. It's a practice that comes from US GAAPs (Generally Accepted Accounting Principles) and has been incorporated into the international IFRS standards. It means that you have to test the book value of your fixed assets (most generally the intangible assets, in particular acquisition goodwill, but also tangible assets in some cases) according to the value they generate.
More specifically, you estimate the future free cash flows (*) generated by the assets under consideration, you calculate the net present value of these cash flows and you compare the NPV to the book value of the assets. If the difference is positive, fine: the assets are worth their book value (more than it, actually) and you don't have to do anything. If negative, you reduce the book value of the assets through an amortization (an exceptional depreciation) so that the residual book value is not higher than the NPV of the free cash flows. The amortization in turn reduces your profit.
(*) free cash flow = net income + depreciations - investments +/- change in working capital