The first thing you should know is what the purpose of the valuation itself, is it for collateral in case you need borrow some money from the bank and the bank need an appraisal report to know the value of your collateral.

Another reason is for management purposes, for accounting purpose, for taxation purposes in case you want to do revaluation of your asset, or you might need an appraisal report for a consolidation purposes or you might take an important decission and you must have an appraisal report to back up your analysis.