Table of Contents or assumption made by management, it is possible that other people applying reasonable judgment to the same facts and circumstances could develop different estimates. Actual results that differ from management’s estimates could have an unfavorable effect on our consolidated financial statements. Management believes the following critical accounting policies reflect the more significant judgments and estimates used in the preparation of the consolidated financial statements: Our revenues are primarily recognized when the customer obtains control of the product sold, which is generally upon shipment or delivery, depending on the delivery terms specified in the sales agreement. Revenues associated with certain instruments and equipment for which installation is complex, and therefore significantly affects the customer’s ability to use and benefit from the product, are recognized when customer acceptance of these installed products has been confirmed. For certain service arrangements, including extended warranty and software maintenance contracts, revenue is recognized ratably over the contract term. The majority of revenues relating to extended warranty contracts associated with certain instruments and equipment is generally recognized within a few years whereas deferred revenue relating to software maintenance contracts is generally recognized over a longer period. Our agreements with customers within certain organizational units including Medication Management Solutions, Diagnostic Systems and Biosciences, contain multiple performance obligations including both products and certain services noted above. Determining whether products and services are considered distinct performance obligations that should be accounted for separately may require judgment. The transaction price for these agreements is allocated to each performance obligation based upon its relative standalone selling price. Standalone selling price is the amount at which we would sell a promised good or service separately to a customer. We generally estimate standalone selling prices using its list prices and a consideration of typical discounts offered to customers. The use of alternative estimates could result in a different amount of revenue deferral. Our gross revenues are subject to a variety of deductions, which include rebates and sales discounts. These deductions represent estimates of the related obligations and judgment is required when determining the impact on gross revenues for a reporting period. Additional factors considered in the estimate of our rebate liability include the quantification of inventory that is either in stock at or in transit to our distributors, as well as the estimated lag time between the sale of product and the payment of corresponding rebates. Goodwill assets are subject to impairment reviews at least annually, or whenever indicators of impairment arise. Intangible assets with finite lives, including developed technology, and other long-lived assets, are periodically reviewed for impairment when impairment indicators are present. We assess goodwill for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment, referred to as a component. Our reporting units generally represent one level below reporting segments. Potential impairment of goodwill is generally identified by comparing the fair value of a reporting unit with its carrying value. Our annual goodwill impairment test performed on July 1, 2019 did not result in any impairment charges, as the fair value of each reporting unit exceeded its carrying value. We generally use the income approach to derive the fair value for impairment assessments. This approach calculates fair value by estimating future cash flows attributable to the assets and then discounting these cash flows to a present value using a risk-adjusted discount rate. We selected this method because we believe the income approach most appropriately measures our income producing assets. This approach requires significant management judgment with respect to future volume, revenue and expense growth rates, changes in working capital use, appropriate discount rates, terminal values and other assumptions and estimates. The estimates and assumptions used are consistent with BD’s business plans. The use of alternative estimates and assumptions could increase or decrease the estimated fair value of the asset, and potentially result in different impacts to BD’s results of operations. Actual results may differ from management’s estimates. BD maintains valuation allowances where it is more likely than not that all or a portion of a deferred tax asset will not be realized. Changes in valuation allowances are included in our tax provision in the period of change. In determining whether a valuation allowance is warranted, management evaluates factors such as prior 38 Income Taxes Impairment of Assets Revenue Recognition