Stocks and work in progressStocks and work in progress are valued at the lower of cost and net realizable value after making due allowance for obsolete and slow-moving stocks. Cost includes all direct costs and an appropriate proportion of fixed and variable overheads. Work-in-progress is reflected in the accounts on a contract by contract basis by recording turnover and related costs as contract activity progressesTaxationIncome tax expense represents the sum of the tax currently payable and deferred tax.The tax currently payable is based on taxable profit for the year. Taxable profit differs from profit as reported in the statement of comprehensive income because of items of income or expense that are taxable or deductible in other year and items that are never taxable or deductible. The company's liability for current tax is calculated using tax rates that have been enacted or substantively enacted by the end of the reporting period.Deferred tax is recognized on timing differences between the carrying amounts of assets and liabilities in the financial statements and the corresponding tax bases used in the computation of taxable profit. Deferred tax liabilities are generally recognized for all taxable timing differences. Deferred tax assets are generally recognized for all deductible temporary differences to the extent that it is probable that taxable profits will be available against which those deductible timing differences can be utilized. The carrying amount of deferred tax assets is reviewed at the end of each reporting period and reduced to the extent that it is no longer probable that sufficient taxable profits will be available to allow all or part of the asset to be recovered.Deferred tax assets and liabilities are measured at the tax rates that are expected to apply in the period in which the liability is settled or the asset realized, based on tax rates (and tax laws) that have been enacted or substantively enacted by the end of the reporting period. Deferred tax liabilities are presented within provisions for liabilities and deferred tax assets within debtors. The measurement of deferred tax liabilities and asset reflects the tax consequences that would follow from the manner in which the Company expects, at the end of the reporting period, to recover or settle the carrying amount of its assets and liabilities.Current or deferred tax for the year is recognized in profit or loss, except when they related to items that are recognized in other comprehensive income or directly in equity, in which case, the current and deferred tax is also recognized in other comprehensive income or directly in equity respectively.