The question is asking how you would go about measuring how well managers are doing their jobs.
One obvious area to mention would be the use of variance analysis. Also, if the company is divisionalised, then you could write a lot about divisional performance measurement.
However, why are you looking at a question for which you do not have an answer? You should be using a Revision Kit from one of the ACCA Approved Publishers – they are full of exam standard questions (together with answers!).