Glassrite Limited has an item of plant which has undergone an impairment review at year end $($December $2020).$ At the review, the following information was produced.

Fair Value of plant: R $1400000$

Costs of disposal: $2\%$ of Selling price.

Revenue and costs per annum for the remaining useful life are noted below:

Year     Revenue $($R $)$     Costs $($R $)$

$2021\mathrm{ \; \; \; 9}60000\mathrm{ \; \; \; \; \; \; 2}40000$

$2022880000220000$

$2023\mathrm{ \; \; \; 7}00000\mathrm{ \; \; \; \; \; \; 2}90000$

A discount rate of $10\%$ is applicable. $($No estimated residual value for the plant$)$

Required

$4\mathrm{.}1$ Calculate the recoverable amount as at $31$ December $2020.(15)$

$4\mathrm{.}2$ How would an entity know when to impair their assets?

 Briefly explain including details on what is required to be done, how often, what steps are to be taken and what information is required and / or should be considered before determining whether an asset is  impaired? $(15)$