ARCH Limited acquired a subsidiary, Curve Limited, ten years ago and goodwill on consolidation is being written off over 20 years. Curve made good profits until two years ago, but in the year to 31 December 2010, made a small loss and in the year to 31 December 2014 made a significant loss. Do you think that this would provide good grounds for an impairment review? What audit steps would you perform to satisfy yourself that the results of the impairment review are valid?