product portfolio; and

 	

 	• 	discount rates.

 

Unanticipated events and circumstances may occur that may affect the accuracy or validity of such assumptions, estimates or actual results.

 

In connection with the purchase price allocations for our acquisitions, we estimate the fair value of the support obligations assumed. The estimated fair value of the support obligations is determined utilizing a cost build-up approach. The cost build-up approach determines fair value by estimating the costs related to fulfilling the obligations plus a normal profit margin. The estimated costs to fulfill the support obligations are based on the historical direct costs related to providing the support services and to correct any errors in the software products acquired. The sum of these costs and operating profit approximates, in theory, the amount that we would be required to pay a third party to assume the support obligation. We do not include any costs associated with selling efforts or research and development or the related fulfillment margins on these costs. Profit associated with any selling efforts is excluded because the acquired entities would have concluded those selling efforts on the support contracts prior to the acquisition date. We also do not include the estimated research and development costs in our fair value determinations, as these costs are not deemed to represent a legal obligation at the time of acquisition.

 

As a result, we did not recognize software license updates and product support revenues related to support contracts in the amounts of $243 million, $179 million and $212 million that would have been otherwise recorded by the acquired businesses as independent entities in fiscal 2009, 2008 and 2007, respectively. Historically, substantially all of our customers, including customers from acquired companies, renew their support contracts when the contracts are eligible for renewal. To the extent these underlying support contracts are renewed, we will recognize the revenues for the full value of the support contracts over the support periods, the substantial majority of which are one year. Had we included costs for our estimated selling and research and development activities and the associated margin for unspecified product upgrades and enhancements to be provided under our assumed support arrangements, the fair values of the support obligations would have been significantly higher than what we had recorded and we would have recorded a higher amount of software license updates and product support revenues both historically and in future periods related to these assumed support arrangements.

 

Other significant estimates associated with the accounting for business combinations include restructuring costs. Restructuring costs are typically comprised of severance costs, costs of consolidating duplicate facilities and contract termination costs. Restructuring expenses are based upon plans that have been committed to by management, but are generally subject to refinement during the purchase price allocation period (generally within one year of the acquisition date). To estimate restructuring expenses, management utilizes