The preparation of financial statements under IFRS requires management to make judgements, assumptions and estimates that affect the application of accounting policies and the reported amounts of assets, liabilities, income and expense. Actual results may differ from these estimates. Assumptions and estimates are reviewed on an ongoing basis and any revisions to them are recognised in the period in which they are revised.
The following items are those that management considers to be critical due to the level of judgement and estimation required:
Revenue and profit recognition
Recognition of revenue and profit is based on judgements made in respect of the ultimate profitability of a contract. Such judgements are arrived at through the use of estimates in relation to the costs and value of work performed to date and to be performed in bringing contracts to completion. These estimates are made by reference to recovery of pre-contract costs, surveys of progress against the construction programme, changes in design and work scope, the contractual terms and site conditions under which the work is being performed, delays, costs incurred, claims received by the Group, external certification of the work performed and the recoverability of any unagreed income from claims and variations.
Management continually reviews the estimated final outturn on contracts and makes adjustments where necessary. Based on the above, management believes it is reasonably possible, on the basis of existing knowledge, that outcomes within the next financial year that are different from these assumptions could require a material adjustment. However, due to the level of uncertainty, combination of cost and income variables and timing across a large portfolio of contracts at different stages of their contract life, it is impracticable to provide a quantitative analysis of the aggregated judgements that are applied at a portfolio level.
Within this portfolio, there are a limited number of long-term contracts where the Group has incorporated significant judgements over revenue and profit, which have been recognised at a level that is considered highly probable not to significantly reverse. However, there are a host of factors affecting potential outcomes in respect of these entitlements which could result in a range of reasonably possible outcomes on these contracts in the following financial year, ranging from a gain of £17,000,000 to a loss of £6,000,000. Management has assessed the range of reasonably possible outcomes on these limited number of contracts based on facts and circumstances that were present and known at the balance sheet date. As with any contract applying long-term contract accounting, these contracts are also affected by a variety of uncertainties that depend on future events, and so often need to be revised as contracts progress.
At the balance sheet date, amounts due from construction contract customers, included in contract assets, trade and other receivables, was £74,898,000 (2021: £16,288,000), see note 3.
Contingent liabilities
On an ongoing basis the Group is a party to various legal disputes, the outcomes of which cannot be assessed with a high degree of certainty. A liability is recognised only where, based on the Group's legal views and advice, it is considered probable that an outflow of resources will be required to settle a present obligation that can be measured reliably. Disclosure of contingent liabilities is made in note 28 unless the possibility of a loss arising is considered remote. These potential liabilities are subject to uncertain future events, may extend over several years and their timing may differ from current assumptions. Management applies its judgement in determining whether or not a liability on the balance sheet should be recognised or a contingent liability should be disclosed.
Retirement benefit obligations
The Group's defined benefit pension scheme has been valued in accordance with IAS 19 'Employee Benefits'. The benefit obligation is calculated using a number of assumptions including forecast discount and mortality rates (as disclosed in note 30). The present value of the benefit obligations is calculated by discounting the benefit obligation using market rates on relevant AA corporate bonds at the balance sheet date.
Significant judgement is required in setting the criteria for the valuation of the liability. Effects of changes in the actuarial assumptions underlying the benefit obligation, discount rates and the difference between expected and actual returns on the scheme's assets are classified as actuarial gains and losses.
The defined benefit obligation recognised at the balance sheet date was £14,396,000 (2021: £22,379,000).
Of the items discussed above, revenue and profit recognition represents the key source of estimation uncertainty.