I'm looking for thoughts around the following scenario;
Company received payment for sale of item and installation of item. The customer has the item and all risks/rewards of the item but installation by an engineer has not taken place yet due to the nature of the item. This was 3 years ago. The customer could still ask the company to undertake the installation. The sales contract is silent on when installation is forfeited. At present revenue on the installation sale is held as deferred revenue on the balance sheet. At what point could the company release to the p&l on the assumption that it is earned? Is there any standard which tackles this situation specifically?