performed. For all license and service arrangements accounted for under the percentage-of-completion method, we determine progress to completion based on actual direct labor hours incurred to date as a percentage of the estimated total direct labor hours required to complete the project. We periodically evaluate the actual status of each project to ensure that the estimates to complete each contract remain accurate. A provision for estimated losses on contracts is made in the period in which the loss becomes probable and can be reasonably estimated. Costs incurred in advance of revenue recognized are recorded as deferred costs on uncompleted contracts. If the amount billed exceeds the amount of revenue recognized, the excess amount is recorded as deferred revenue. Revenue recognized in any period is dependent on our progress toward completion of projects in progress. Significant management judgment and discretion are used to estimate total direct labor hours. Any changes in or deviations from these estimates could have a material effect on the amount of revenue we recognize in any period.



   Accounts Receivable

 

   We maintain an allowance for doubtful accounts receivable for estimated losses resulting from the inability of our customers to make required payments. Management determines this allowance, which consists of an amount identified for specific customer issues as well as an amount based on overall estimated exposure. Our accounts receivable are highly concentrated and make us vulnerable to adverse changes in our customers' businesses, and to downturns in the industry and the worldwide economy.  For example, one customer accounted for approximately 18% of our accounts receivable balance at January 25, 2009, and we continue to work directly with more foreign customers and it may be difficult to collect accounts receivable from them. Our overall estimated exposure excludes significant amounts that are covered by credit insurance and letters of credit. If the financial condition of our customers, the financial institutions providing letters of credit, or our credit insurance carrier were to deteriorate, resulting in an impairment of their ability to make payments, additional allowances may be required that could adversely affect our operating results. This risk is heightened during periods when economic conditions worsen, such as the current period when the worldwide economy is experiencing a downturn. The current financial turmoil affecting the banking system and financial markets and the possibility that financial institutions may consolidate or go out of business have resulted in a tightening in the credit markets, a low level of liquidity in many financial markets, and extreme volatility in fixed income, credit, currency and equity markets. There could be a number of follow-on effects from the credit crisis on our business, including inability of customers, including channel partners, to obtain credit to finance purchases of our products and/or customer, insolvencies and failure of financial institutions, which may negatively impact our financial results. Furthermore, there can be no assurance that we will be able to obtain