Table of Contents

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549



FORM 10-Q

or

Commission File Number 000-31311

PDF SOLUTIONS, INC.

(Exact name of Registrant as Specified in its Charter)

(408) 280-7900

(Registrant’s Telephone Number, Including Area Code)

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☑ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☑ No  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer,  a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicated by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☑

There were 32,795,326 shares of the Registrant’s Common Stock outstanding as of May 2, 2020.

TABLE OF CONTENTS

1. BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation 

The interim unaudited condensed consolidated financial statements included herein have been prepared by PDF Solutions, Inc. (the “Company”) pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”), including the instructions to the Quarterly Report on Form 10-Q and Article 10 of Regulation S-X. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted. The interim unaudited condensed consolidated financial statements reflect, in the opinion of management, all adjustments necessary (consisting only of normal recurring adjustments), to present a fair statement of results for the interim periods presented. The operating results for any interim period are not necessarily indicative of the results that may be expected for other interim periods or the full fiscal year. The accompanying interim unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.

The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries after the elimination of all intercompany balances and transactions.

The condensed consolidated balance sheet at December 31, 2019, has been derived from the audited consolidated financial statements but does not include all disclosures required by accounting principles generally accepted in the United States of America.

Reclassification of Prior Period Amounts

Certain prior period amounts have been reclassified to conform to the current year presentation of reporting amortization of costs capitalized to obtain revenue contracts, operating lease right-of-use assets, and operating lease liabilities on the Condensed Consolidated Statements of Cash Flows. This reclassification had no effect on the Company’s reported net loss or net cash used in operating activities.

Change in Presentation

In the fourth quarter of fiscal 2019, in order to enhance the transparency of our revenue reporting, the Company updated its Condensed Consolidated Statements of Comprehensive Loss to change its historical presentation of revenue categories. Previously, the Company presented revenue on two lines: Solutions and Gainshare performance incentives.  Included within Solutions, was revenue from software and related revenue, SaaS solutions, Design-for-Inspection (DFI™) licenses, and fixed-price project-based solution implementation services. The previous Gainshare performance incentive category included only revenue from performance incentive programs. The Company now presents revenue in the following categories: Analytics and Integrated Yield Ramp.  Integrated Yield Ramp revenue is comprised of all revenue from the Company’s Integrated Yield Ramp services engagements that include performance incentives based on customers’ yield achievement, i.e. both fixed-fees and Gainshare royalty from such engagements. Analytics comprises all other revenue, including from the Company’s licenses and services for Exensio Software, Exensio SaaS, DFI™ and Characterization Vehicle (CV) systems that do not include performance incentives based on customers’ yield achievement.

The change in presentation of revenue does not change the Company’s net revenues or total cost of net revenues. The following table shows reclassified amounts to conform to the current period’s presentation (in thousands):

Since certain costs of revenues are attributed to both Analytics and Integrated Yield Ramp revenue categories, the Company believes it is more appropriate and meaningful to present the Condensed Consolidated Statements of Comprehensive Loss under a one-step presentation format that excludes any measure of gross margin. In the fourth quarter of fiscal 2019, the Company elected to change its Condensed Consolidated Statements of Comprehensive Loss presentation from a two-step presentation, where total costs of revenues was deducted from total revenues to report a gross profit line, to a one-step presentation, where total costs and expenses are deducted from total revenues. The change in presentation does not change previously presented amounts for costs of revenues, operating expenses and other expenses (income), or loss before income taxes.

Use of Estimates 

The preparation of financial statements in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates in these financial statements include revenue recognition, impairment of goodwill and long-lived assets, accounting for stock-based compensation expense, and income taxes. Actual results could differ from those estimates.

The global COVID-19 pandemic has impacted the operations and purchasing decisions of companies worldwide. It also has created and may continue to create significant uncertainty in the global economy. The Company has undertaken measures to protect its employees, partners, customers, and vendors. In addition, the Company’s personnel worldwide are subject to various travel restrictions, which limit the ability of the Company to provide services to customers and affiliates. This impacts the Company's normal operations. To date, the Company has been able to provide uninterrupted access to its products and services due to its globally distributed workforce, many of whom are working remotely, and its pre-existing infrastructure that supports secure access to the Company’s internal systems. If, however, the COVID-19 pandemic has a substantial impact on the productivity of the Company’s employees or its partners’ or customers’ decision to use the Company’s products and services, the results of the Company’s operations and overall financial performance may be adversely impacted. The duration and extent of the impact from the COVID-19 pandemic depends on future developments that cannot be accurately predicted at this time. As of the date of issuance of the financial statements, the Company is not aware of any specific event or circumstance that would require updates to the Company’s estimates and judgments or revisions to the carrying value of its assets or liabilities. These estimates may change, as new events occur and additional information is obtained, and are recognized in the condensed consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to the financial statements.

Recently Adopted Accounting Standards

Intangibles – Goodwill and Other

In January 2017, the Financial Accounting Standards Board (or FASB) issued Accounting Standards Update (ASU) No. 2017-04, Intangibles – Goodwill and Other (Topic 350). This standard eliminates step 2 from the annual goodwill impairment test. This update is effective for the Company beginning in the first quarter of 2020. The Company adopted this standard on January 1, 2020, and it did not have a material impact on its condensed consolidated financial statements and footnote disclosures.

Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract

Accounting Standards Not Yet Effective

 In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13), which requires measurement and recognition of expected credit losses for financial assets held at the reporting date based on external information, or a combination of both relating to past events, current conditions, and reasonable and supportable forecasts. ASU No. 2016-13 replaces the existing incurred loss impairment model with a forward-looking expected credit loss model which will result in earlier recognition of credit losses. Subsequent to the issuance of ASU No. 2016-13, the FASB issued ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments – Credit Losses, ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments – Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instrument, ASU No. 2019-05, Financial Instruments – Credit Losses (Topic 326) Targeted Transition Relief, ASU No. 2016-13, the FASB issued ASU No. 2019-10 Financial Instruments-Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842), and ASU No. 2019-11 Codification Improvements to Topic 326, Financial Instruments-Credit Losses. The subsequent ASUs do not change the core principle of the guidance in ASU No. 2016-13. Instead, these amendments are intended to clarify and improve operability of certain topics included within ASU No. 2016-13.

Additionally, ASU No. 2019-10 defers the effective date for the adoption of the new standard on credit losses for public filers that are considered small reporting companies (“SRC”) as defined by the SEC to fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, which will be fiscal 2023 for the Company if it continue to be classified as a SRC. In February 2020, the FASB issued ASU 2020-02, which provides guidance regarding methodologies, documentation, and internal controls related to expected credit losses. The subsequent amendments will have the same effective date and transition requirements as ASU No. 2016-13. Early adoption is permitted. Topic 326 requires a modified retrospective approach by recording a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. While the Company is currently evaluating the impact of Topic 326, the Company does not expect the adoption of this ASU to have a material impact on its condensed consolidated financial statements and the related disclosure.

In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740) related to simplifying the accounting for income taxes. The guidance is effective for the Company beginning in the first quarter of 2021 on a prospective basis. Early adoption is permitted.  The Company is currently evaluating the impact of this ASU, and does not anticipate that the adoption of this ASU will have a significant impact on its consolidated financial statements or the related disclosures.

In January 2020, the FASB issued ASU No. 2020-01-Investments-Equity Securities (Topic 321), Investments-Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815)-Clarifying the Interactions between Topic 321, Topic 323, and Topic 815. This ASU clarifies the interaction between accounting standards related to equity securities (ASC 321), equity method investments (ASC 323), and certain derivatives (ASC 815). The amendments in this ASU are effective for fiscal years beginning after December 15, 2020. The Company does not anticipate that the adoption of this ASU will have a significant impact on its condensed consolidated financial statements or the related disclosures.

2. REVENUE FROM CONTRACTS WITH CUSTOMERS

The Company derives revenue from two sources: Analytics revenue and Integrated Yield Ramp revenue.

The Company recognizes revenue in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standard Codification (“ASC”) Topic 606, Revenue from Contracts with Customers, and its related amendments (collectively known as “ASC 606”). ASC 606 outlines a single comprehensive model to use in accounting for revenue arising from contracts with customers. Revenue is recognized when control of products or services is transferred to customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those promised products or services.

The Company determines revenue recognition through the following five steps:

The Company accounts for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance, and collectability of consideration is probable.

Contracts with multiple performance obligations

The Company enters into contracts that can include various combinations of licenses, products and services, some of which are distinct and are accounted for as separate performance obligations. For contracts with multiple performance obligations, the Company allocates the transaction price of the contract to each performance obligation on a relative basis using standalone selling price.

Analytics Revenue

Analytics revenue is derived from the following primary offerings: licenses and services for Exensio Software, Exensio SaaS, DFI™ and CV systems that do not include performance incentives based on customers’ yield achievement.

Revenue from standalone Exensio Software is recognized depending on whether the license is perpetual or time-based. Perpetual (one-time charge) license software is recognized at the time of the inception of the arrangement when control transfers to the customers, if the software license is distinct from the services offered by us. Revenue from post-contract support is recognized over the contract term on a straight-line basis, because we are providing (i) support and (ii) unspecified software updates on a when-and-if available basis over the contract term. Revenue from time-based-licensed software is allocated to each performance obligation and is recognized either at a point in time or over time as follows. The license component is recognized at the time when control transfers to the customer, with the post-contract support component recognized ratably over the committed term of the contract. For contracts with any combination of licenses, support, and other services, distinct performance obligations are accounted for separately. For contracts with multiple performance obligations, we allocate the transaction price of the contract to each performance obligation on a relative basis using standalone selling price (or SSP) attributed to each performance obligation.

Revenue from Exensio SaaS arrangements, which allow for the use of a cloud-based software product or service over a contractually determined period of time without taking possession of software, is accounted for as subscriptions and is recognized as revenue ratably, on a straight-line basis, over the subscription period beginning on the date the service is first made available to customers.

Revenue from DFI™ and CV systems that do not include performance incentives based on customers’ yield achievement is recognized primarily as services are performed. Where there are distinct performance obligations, the Company allocates revenue to all deliverables based on their standalone selling prices, or SSP. For these contracts with multiple performance obligations, the Company allocate the transaction price of the contract to each performance obligation on a relative basis using SSP attributed to each performance obligation. Where there are not discrete performance obligations, historically, revenue is primarily recognized as services are performed using a percentage of completion method based on costs or labor-hours inputs, whichever is the most appropriate measure of the progress towards completion of the contract.

Integrated Yield Ramp Revenue

The Integrated Yield Ramp revenue is derived from the Company’s fixed-fee engagements that include performance incentives based on customers’ yield achievement and Gainshare royalties, typically based on customer’s wafer shipments, pertaining to these fixed-price contracts.

Revenue under these project–based contracts, which are delivered over a specific period of time typically for a fixed fee component paid on a set schedule, is recognized as services are performed using a percentage of completion. Similar to the services provided in connection with CV systems that are contributing to Analytics revenue, due to the nature of the work performed in these arrangements, the estimation of percentage of completion method is complex and subject to many variables that require significant judgement. Please refer to “Significant Judgments” section of this Note for further discussion.

The Gainshare royalty contained in IYR contracts is a variable fee related to continued usage of the Company’s intellectual property (“IP”) after the fixed-fee service period ends, based on the customers’ yield achievement. Revenue derived from Gainshare is contingent upon the Company’s customers reaching certain defined production yield levels. Gainshare royalty periods are generally subsequent to the delivery of all contractual services and performance obligations. The Company records Gainshare as a usage-based royalty derived from customers’ usage of intellectual property and records it in the same period in which the usage occurs.

Disaggregation of Revenue

The Company disaggregates revenue from contracts with customers into the timing of the transfer of goods and services and the geographical regions. The Company determined that disaggregating revenue into these categories achieves the disclosure objective to depict how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors.

The Company’s performance obligations are satisfied either over time or at a point-in-time. The following table represents a disaggregation of revenue by timing of revenue:

International revenues accounted for approximately 59% of our total revenues for the three months ended March 31, 2020 as compared to 55% for the three months ended March 31, 2019. See Note 10. Customer and Geographic Information.

Significant Judgments

Judgments and estimates are required under ASC 606. Due to the complexity of certain contracts, the actual revenue recognition treatment required under ASC 606 for the Company’s arrangements may be dependent on contract-specific terms and may vary in some instances.

For revenue under project-based contracts for fixed-price implementation services, revenue is recognized as services are performed using a percentage-of-completion method based on costs or labor-hours input method, whichever is the most appropriate measure of the progress towards completion of the contract. Due to the nature of the work performed in these arrangements, the estimation of percentage of completion method is complex, subject to many variables and requires significant judgment. Key factors reviewed by the Company to estimate costs to complete each contract are future labor and product costs and expected productivity efficiencies. If circumstances arise that change the original estimates of revenues, costs, or extent of progress toward completion, revisions to the estimates are made. These revisions may result in increases or decreases in estimated revenues or costs, and such revisions are reflected in revenue on a cumulative catch-up basis in the period in which the circumstances that gave rise to the revision become known.

The Company’s contracts with customers often include promises to transfer products, licenses software and provide services, including professional services, technical support services, and rights to unspecified updates to a customer. Determining whether licenses and services are distinct performance obligations that should be accounted for separately, or not distinct and thus accounted for together, requires significant judgment. The Company rarely licenses software on a standalone basis, so the Company is required to estimate the range of SSPs for each performance obligation. In instances where SSP is not directly observable because the Company does not license the software or sell the service separately, the Company determines the SSP using information that may include market conditions and other observable inputs. The Company, in some cases, has more than one SSP for individual performance obligations. In these instances, the Company may use information such as the size of the customer and geographic region of the customer in determining the SSP.

The Company is required to record Gainshare royalty revenue in the same period in which the usage occurs. Because the Company generally does not receive the acknowledgment reports from its customers during a given quarter within the time frame necessary to adequately review the reports and include the actual amounts in quarterly results for such quarter, the Company accrues the related revenue based on estimates of customers underlying sales achievement. The Company’s estimation process can be based on historical data, trends, seasonality, changes in the contract rate, knowledge of the changes in the industry and changes in the customer’s manufacturing environment learned through discussions with customers and sales personnel. As a result of accruing revenue for the quarter based on such estimates, adjustments will be required in the following quarter to true-up revenue to the actual amounts reported.

Contract Balances  

The Company performs its obligations under a contract with a customer by licensing software or providing services in exchange for consideration from the customer. The timing of the Company’s performance often differs from the timing of the customer’s payment, which results in the recognition of a receivable, a contract asset or a contract liability.

The Company classifies the right to consideration in exchange for software or services transferred to a customer as either a receivable or a contract asset. A receivable is a right to consideration that is unconditional, as compared to a contract asset, which is a right to consideration that is conditional upon factors other than the passage of time. The majority of the Company’s contract assets represent unbilled amounts related to fixed-price service contracts when the revenue recognized exceeds the amount billed to the customer. The contract assets are generally classified as current and are recorded on a net basis with deferred revenue (i.e. contract liabilities) at the contract level. At March 31, 2020 and December 31, 2019, contract assets of $1.4 million and $3.6 million, respectively, are included in prepaid expenses and other current assets in the Condensed Consolidated Balance Sheets. The Company did not record any asset impairment charges related to contract assets during the months ended March 31, 2020 and 2019.

Deferred revenues consist substantially of amounts invoiced in advance of revenue recognition and are recognized as the revenue recognition criteria are met. Deferred revenues that will be recognized during the succeeding twelve-month period are recorded as current deferred revenues and the remaining portion is recorded as non-current deferred revenues in the Condensed Consolidated Balance Sheets. Revenue recognized for the three months ended March 31, 2020 and 2019, that was included in the deferred revenues and billings in excess of recognized revenues balances at the beginning of each reporting period was $4.6 million and $3.3 million, respectively.

At March 31, 2020, the aggregate amount of the transaction price allocated to the remaining performance obligations related to customer contracts that were unsatisfied or partially unsatisfied was approximately $68.5 million. Given the applicable contract terms, the majority of this amount is expected to be recognized as revenue over the next two years, with the remainder in the following five years.  This amount does not include contracts to which the customer is not committed, nor contracts for which we recognize revenue equal to the amount we have the right to invoice for services performed, or future sales-based or usage-based royalty payments in exchange for a license of intellectual property.  This amount is subject to change due to future revaluations of variable consideration, terminations, other contract modifications, or currency adjustments.  The estimated timing of the recognition of remaining unsatisfied performance obligations is subject to change and is affected by changes to the scope, change in timing of delivery of products and services, or contract modifications.

The Company capitalizes the incremental costs to obtain or fulfill a contract with a customer, including direct sales commissions and related fees, when it expects to recover those costs. Amortization expense related to these capitalized costs is recognized over the period associated with the revenue from which the cost was incurred. Total capitalized direct sales commission costs included in prepaid expenses and other current assets in the accompanying Condensed Consolidated Balance Sheets as of March 31, 2020 and December 31, 2019 were $0.4 million. Total capitalized direct sales commission costs included in other non-current assets in the accompanying Condensed Consolidated Balance Sheets as of March 31, 2020 and December 31, 2019 were $0.8 million and $0.4 million, respectively. Amortization of these assets during each of the three months ended March 31, 2020 and 2019 was $0.1 million. There was no impairment loss in relation to the costs capitalized for the periods presented.

Certain eligible initial project costs are capitalized when the costs relate directly to the contract, the costs generate or enhance resources of the Company that will be used in satisfying the performance obligation in the future, and the costs are expected to be recovered. These costs primarily consist of transition and set-up costs related to the installation of systems and processes and other deferred fulfillment costs eligible for capitalization.  Capitalized costs are amortized consistent with the transfer to the customer of the services to which the asset relates and recorded as a component of cost of revenues. The Company also incurs certain direct costs to provide services in relation to the specific anticipated contracts. The Company recognizes such costs as a component of costs of revenues, the timing of which is dependent upon identification of a contract arrangement. The Company also defers costs from arrangements that required it to defer the revenues, typically due to the pattern of transfer of the performance obligations in the contract. These costs are recognized in proportion to the related revenue. At the end of the reporting period, the Company evaluates its deferred costs for their probable recoverability. The Company recognizes impairment of deferred costs when it is determined that the costs no longer have future benefits and are no longer recoverable. There was no impairment loss in relation to the costs capitalized for the periods presented. Deferred costs balance included in prepaid expenses and other current assets in the accompanying Condensed Consolidated Balance Sheets as of March 31, 2020 and December 31, 2019 was $0.3 million.  Deferred costs balance included in other non-current assets in the accompanying Condensed Consolidated Balance Sheets as of March 31, 2020 was immaterial and was $0.2 million as of December 31, 2019.

Practical Expedients

The Company does not adjust transaction price for the effects of a significant financing component when the period between the transfers of the promised good or service to the customer and payment for that good or service by the customer is expected to be one year or less. The Company assessed each of its revenue generating arrangements in order to determine whether a significant financing component exists, and determined its contracts did not include a significant financing component for the three months ended March 31, 2020 and 2019.

3. BALANCE SHEET COMPONENTS

Accounts receivable

Accounts receivable include amounts that are unbilled at the end of the period that are expected to be billed and collected within 12-month period. Unbilled accounts receivable, included in accounts receivable, totaled $9.4 million and $7.4 million as of March 31, 2020, and December 31, 2019, respectively. Unbilled accounts receivable that are not expected to be billed and collected during the succeeding 12-month period are recorded in other non-current assets and totaled $2.8 million and $4.1 million as of March 31, 2020, and December 31, 2019, respectively.

Property and equipment

Property and equipment, net consist of the following (in thousands):

Test equipment includes DFI™ assets at customer sites that are contributing to DFI™ revenues. The construction-in-progress balance related to construction of DFI™ assets totaled $17.7 million and $16.6 million as of March 31, 2020 and December 31, 2019, respectively. Depreciation and amortization expense for the three months ended March 31, 2020 and 2019 was $1.7 million and $1.3 million, respectively.

Goodwill and Intangible Assets

As of March 31, 2020, and December 31, 2019, the carrying amount of goodwill was $2.3 million.

Intangible assets balance was $5.9 million and $6.2 million as of March 31, 2020 and December 31, 2019, respectively. Intangible assets as of March 31, 2020 and December 31, 2019 consist of the following (in thousands):

The weighted average amortization period for acquired identifiable intangible assets was 6.0 years as of March 31, 2020. Intangible asset amortization expense was $0.3 million during each of the three months ended March 31, 2020 and 2019, which was recorded in other expense (income), net in the Company’s Condensed Consolidated Statements Comprehensive Loss. The Company expects annual amortization of acquired identifiable intangible assets to be as follows (in thousands):

Intangible assets are amortized over their useful lives unless these lives are determined to be indefinite. Intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. During the three months ended March 31, 2020, there were no indicators of impairment related to the Company’s intangible assets.

4. LEASES

The Company leases administrative and sales offices and certain equipment under noncancellable operating leases, which contain various renewal options and, in some cases, require payment of common area costs, taxes and utilities. These operating leases expire at various times through 2028. The Company had no leases that were classified as a financing lease as of March 31, 2020 and December 31, 2020.

Leases with an initial term of 12 months or less are not recorded on the balance sheets, and the Company recognizes lease expense for these leases on a straight-line basis over the lease term. Long-term operating leases are included in operating lease right-of-used (ROU) assets and operating lease liabilities in the Company’s Condensed Consolidated Balance Sheets.

ROU assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized based on the present value of remaining lease payments over the lease term. In determining the present value of lease payments, implicit rate must be used when readily determinable. As the Company’s leases do not provide implicit rates, at the date of the Company’s adoption of the new lease standard, the discount rate is calculated using the Company’s incremental borrowing rate determined based on the information available. The operating lease ROU asset also includes any lease payments made and excludes lease incentives or tenant improvement allowance. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating lease expense for lease payments is recognized on a straight-line basis over the lease term. Variable lease payment amounts that cannot be determined at the commencement of the lease such as increases in lease payments based on changes in index rates or usage, and common area maintenance costs are not included in the ROU assets or operating lease liabilities. These are expensed as incurred and recorded as variable lease expense. 

Lease expense for the three months ended March 31, 2020 and 2019 was comprised of the following (in thousands):

Supplemental balance sheets information related to leases was as follows:

Maturity of operating lease liabilities as of March 31, 2020, are as follows (in thousands):

5. STOCKHOLDERS’ EQUITY

Stock Repurchase Program 

On May 29, 2018, the Board of Directors terminated the 2016 stock repurchase program, and adopted a new program (the “2018 Program”) to repurchase up to $25.0 million of the Company’s common stock both on the open market and in privately negotiated transactions over the next two years. During the three months ended March 31, 2020, no shares were repurchased under the 2018 program. During the three months ended March 31, 2019, the Company repurchased approximately 314,000 shares at an average price of $12.46 per share, for $3.9 million under the 2018 program. Under the 2018 program, as of March 31, 2020, $15.2 million of the Company's common stock remained available for future repurchases.

6. EMPLOYEE BENEFIT PLANS

On March 31, 2020, the Company had the following stock-based compensation plans:

Employee Stock Purchase Plan

In July 2001, the Company adopted a ten-year Employee Stock Purchase Plan (as amended, the “Purchase Plan”) under which eligible employees can contribute up to 10% of their compensation, as defined in the Purchase Plan, towards the purchase of shares of PDF common stock at a price of 85% of the lower of the fair market value at the beginning of the offering period or the end of the purchase period. The Purchase Plan consists of twenty-four-month offering periods with four six-month purchase periods in each offering period. Under the Purchase Plan, on January 1 of each year, starting with 2002, the number of shares reserved for issuance will automatically increase by the lesser of (1) 675,000 shares, (2) 2% of the Company’s outstanding common stock on the last day of the immediately preceding year, or (3) the number of shares determined by the board of directors. At the annual meeting of stockholders on May 18, 2010, the Company’s stockholders approved an amendment to the Purchase Plan to extend it through May 17, 2020.

On April 26, 2020, the Company’s Board of Directors approved an amendment to the Purchase Plan to extend it through June 22, 2030, subject to the approval of the Company’s stockholders.

 The Company estimated the fair value of purchase rights granted under the Purchase Plan during the period using the Black-Scholes-Merton option-pricing model with the following weighted average assumptions, resulting in the following weighted average fair values:

During the three months ended March 31, 2020 and 2019, a total of approximately 89,000 and 88,000 shares, respectively, were issued at a weighted-average purchase price of $9.02 and $8.93 per share, respectively. As of March 31, 2020, there was $0.7 million of unrecognized compensation cost related to the Purchase Plan. That cost is expected to be recognized over a weighted average period of 1.01 years. As of March 31, 2020, 5.8 million shares were available for future issuance under the Purchase Plan.

Stock Incentive Plans

On November 16, 2011, the Company’s stockholders initially approved the 2011 Stock Incentive Plan, which has been amended and restated and approved by the Company’s stockholders a number of times since then (as amended, the “2011 Plan”). Under the 2011 Plan, the Company may award stock options, stock appreciation rights, stock grants or stock units covering shares of the Company’s common stock to employees, directors, non-employee directors and contractors. The aggregate number of shares reserved for awards under this plan is 10,300,000 shares, plus up to 3,500,000 shares previously issued under the 2001 Stock Plan adopted by the Company in 2001, which expired in 2011 (the “2001 Plan”) that are (i) forfeited or (ii) repurchased by the Company or shares subject to awards previously issued under the 2001 Plan that expire or that terminate without having been exercised or settled in full on or after November 16, 2011. In case of awards other than options or stock appreciation rights (“SARs”), the aggregate number of shares reserved under the 2011 Plan will be decreased at a rate of 1.33 shares issued pursuant to such awards. The exercise price for stock options must generally be at prices no less than the fair market value at the date of grant. Stock options generally expire ten years from the date of grant and become vested and exercisable over a four-year period.

On April 26, 2020 the Company’s Board of Directors amended the 2011 Plan, subject to the approval of the Company’s stockholder, to increase the number of shares reserved for awards under it to a total of 11,550,000 shares, which is an increase of an additional 1,250,000 shares and extend the term of the 2011 Plan through June 22, 2030.

In 2003, in connection with its acquisition of IDS Systems Inc., the Company assumed IDS’ 2001 Stock Option / Stock Issuance Plan (the “IDS Plan”). The IDS Plan expired in 2011. Stock options granted under the 2001 Plan and IDS Plan generally expire ten years from the date of grant and become vested and exercisable over a four-year period. Although no new awards may be granted under the 2001 Plan or IDS Plan, awards made under the 2001 Plan and IDS Plan that are currently outstanding remain subject to the terms of each such plan.

As of March 31, 2020, 10.8 million shares of common stock were reserved to cover stock-based awards under the 2011 Plan, of which 3.4 million shares were available for future grant. The number of shares reserved and available under the 2011 Plan includes 0.5 million shares that were subject to awards previously made under the 2001 Plan and were forfeited, expired or repurchased by the Company after the adoption of the 2011 Plan through March 31, 2020. As of March 31, 2020, there were no outstanding awards that had been granted outside of the 2011, 2001 or the IDS Plans (collectively, the “Stock Plans”).

The Company estimated the fair value of share-based awards granted under the 2011 Stock Plan during the period using the Black-Scholes-Merton option-pricing model with the following weighted average assumptions, resulting in the following weighted average fair values:

Stock-based compensation is estimated at the grant date based on the award’s fair value and is recognized on a straight-line basis over the vesting periods, generally four years. Stock-based compensation expense before taxes related to the Company’s stock plans and employee stock purchase plan was allocated as follows (in thousands): 

The stock-based compensation expense in the table above includes immaterial expense or credit adjustments related to cash-settled SARs granted to certain employees. The Company accounted for these awards as liability awards and the amount was included in accrued compensation and related benefits. Stock-based compensation capitalized in the capitalized software development costs, which were included in the Property and Equipment, net, was approximately $0.1 million at March 31, 2020.

 Additional information with respect to options under the Stock Plans during the three months ended March 31, 2020, was as follows:

The aggregate intrinsic value in the table above represents the total intrinsic value based on the Company’s closing stock price of $11.72 per share as of March 31, 2020. The total intrinsic value of options exercised during the three months ended March 31, 2020, was $0.1 million.

As of March 31, 2020, there was $0.7 million of total unrecognized compensation cost related to unvested stock options. That cost is expected to be recognized over a weighted average period of 2.7 years. The total fair value of shares vested during the three months ended March 31, 2020, was $0.1 million.

Nonvested restricted stock units activity during the three months ended March 31, 2020, was as follows:

As of March 31, 2020, there was $18.2 million of total unrecognized compensation cost related to nonvested restricted stock units. That cost is expected to be recognized over a weighted average period of 2.6 years. Restricted stock units do not have rights to dividends prior to vesting.

7. RESTRUCTURING CHARGES

On September 27, 2018, the Board of Directors of the Company approved a reduction in its workforce to reduce expenses and align its operations with evolving business needs. Notifications to the affected employees began on October 24, 2018.

From inception of the restructuring plan to March 31, 2020, the Company has recorded restructuring charges of $0.7 million, primarily consisting of employee separation charges.  As of March 31, 2020, the Company has substantially completed the implementation of the restructuring plan, and the remaining charges expected to be incurred are not expected to be significant.

The following table summarizes the activities of restructuring liabilities under this plan (in thousands): 

Cash payments for the remaining restructuring liabilities as of March 31, 2019 were paid in the second quarter of fiscal 2019. 

8. INCOME TAXES  

Income tax benefit increased $3.4 million for the three months ended March 31, 2020, to a $3.5 million income tax benefit as compared to an income tax benefit of $0.1 million for the three months ended March 31, 2019. The Company’s effective tax rate benefit was 87% and 4% for the three months ended March 31, 2020 and 2019, respectively. The Company’s effective tax rate benefit increased in the three months ended March 31, 2020, as compared to the same period in 2019, primarily due to a  favorable increase in excess tax benefits related to employee stock compensation and an income tax benefit recorded to carryback net operating losses (NOLs), pursuant to the provisions of Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) passed on March 27, 2020, which allows any federal net operating losses generated in years beginning after December 31, 2017 and before January 1, 2021 to be carried back up to five taxable years to offset taxable income in the prior periods. 

The Company’s total amount of unrecognized tax benefits, excluding interest and penalties, as of March 31, 2020, was $13.0 million, of which $7.4 million, if recognized, would affect the Company’s effective tax rate. The Company’s total amount of unrecognized tax benefits, excluding interest and penalties, as of December 31, 2019, was $13.6 million, of which $7.9 million, if recognized, would affect the Company’s effective tax rate. As of March 31, 2020, the Company has recorded unrecognized tax benefits of $2.6 million, including interest and penalties of $0.8 million, as long-term taxes payable in its Condensed Consolidated Balance Sheet. The remaining $11.2 million has been recorded net of our deferred tax assets, of which $5.6 million is subject to a full valuation allowance. 

The valuation allowance was approximately $10.0 million and $10.5 million as of March 31, 2020, and December 31, 2019, respectively, which was related to California R&D tax credits and California net operating losses related to our acquisition of Syntricity that we currently do not believe are more likely than not to be ultimately realized.

The Company conducts business globally and, as a result, files numerous consolidated and separate income tax returns in the U.S. federal, various state and foreign jurisdictions. Because the Company used some of the tax attributes carried forward from previous years to tax years that are still open for audit, the federal and California statute of limitations remains open for all tax years since 1999 and 2002, respectively. The Company is not currently subject to an income tax examination or under audit in any jurisdiction.

9. NET LOSS PER SHARE

Basic net loss per share is computed by dividing net loss by weighted average number of common shares outstanding for the period (excluding outstanding stock options and shares subject to repurchase). Diluted net loss per share is computed using the weighted-average number of common shares outstanding for the period plus the potential effect of dilutive securities which are convertible into common shares (using the treasury stock method), except in cases in which the effect would be anti-dilutive. The following is a reconciliation of the numerators and denominators used in computing basic and diluted net loss per share (in thousands except per share amount): 

For the periods ended March 31, 2020 and 2019, because the Company was in a loss position, basic net loss per share is the same as diluted net loss per share as the inclusion of the potential common shares would have been anti-dilutive.

The following table sets forth potential shares of common stock that are not included in the diluted net loss per share calculation above because to do so would be anti-dilutive for the periods indicated (in thousands):

10. CUSTOMER AND GEOGRAPHIC INFORMATION

Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or group, in deciding how to allocate resources and in assessing performance.

The Company’s chief operating decision maker, the chief executive officer, reviews discrete financial information presented on a consolidated basis for purposes of regularly making operating decisions, allocation of resources, and assessing financial performance. Accordingly the Company considers itself to be in one operating and reporting segment, specifically the provision of services for differentiated data and analytics solutions to the semiconductor and electronics industries.

The Company had revenues from an individual customer in excess of 10% of total revenues as follows: 

The Company had gross accounts receivable from individual customers in excess of 10% of gross accounts receivable as follows: 

Revenues from customers by geographic area based on the location of the customers’ work sites are as follows (in thousands):

Long-lived assets, net by geographic area are as follows (in thousands):

11. FAIR VALUE MEASUREMENTS

Fair value is the exit price, or the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants as of the measurement date. The multiple assumptions used to value financial instruments are referred to as inputs, and a hierarchy for inputs used in measuring fair value is established, that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs reflect assumptions market participants would use in pricing an asset or liability based on market data obtained from independent sources while unobservable inputs reflect a reporting entity’s pricing based upon its own market assumptions. These inputs are ranked according to a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels.

The following table represents the Company’s assets measured at fair value on a recurring basis as of March 31, 2020, and the basis for that measurement (in thousands):

The following table represents the Company’s assets measured at fair value on a recurring basis as of December 31, 2019, and the basis for that measurement (in thousands):

The Company enters into foreign currency forward contracts to reduce the exposure to foreign currency exchange rate fluctuations on certain foreign currency denominated monetary assets and liabilities, primarily on third-party accounts payables and intercompany balances. The primary objective of the Company’s hedging program is to reduce volatility of earnings related to foreign currency exchange rate fluctuations. The counterparty to these foreign currency forward contracts is a financial institution that the Company believes is creditworthy, and therefore, the Company believes the credit risk of counterparty nonperformance is not significant. These foreign currency forward contracts are not designated for hedge accounting treatment.

Therefore, the change in fair value of these contracts is recorded into earnings as a component of other expense (income), net, and offsets the change in fair value of the foreign currency denominated assets and liabilities, which is also recorded in other expense (income), net. The Company recognized a realized loss of $0.3 million during each of the three months ended March 31, 2020 and 2019, which was recorded in other expense (income), net in the Company’s Condensed Consolidated Statements Comprehensive Loss.  

The Company carries these derivatives financial instruments on its Condensed Consolidated Balance Sheets at their fair values. The Company’s foreign currency forward contracts are classified as Level 2 because it is not actively traded and the valuation inputs are based on quoted prices and market observable data of similar instruments. As of March 31, 2020 and December 31, 2019, the Company had no outstanding forward contracts.  

12. COMMITMENTS AND CONTINGENCIES

Indemnifications — The Company generally provides a warranty to its customers that its software will perform substantially in accordance with documented specifications typically for a period of 90 days following initial delivery of its products. The Company also indemnifies certain customers from third-party claims of intellectual property infringement relating to the use of its products. Historically, costs related to these guarantees have not been significant. The Company is unable to estimate the maximum potential impact of these guarantees on its future results of operations.

 Purchase obligations — The Company has purchase obligations with certain suppliers for the purchase of goods and services entered in the ordinary course of business. As of March 31, 2020, total outstanding purchase obligations were $12.8 million, the majority of which due within the next 24 months.

Indemnification of Officers and Directors  — As permitted by the Delaware general corporation law, the Company has included a provision in its certificate of incorporation to eliminate the personal liability of its officers and directors for monetary damages for breach or alleged breach of their fiduciary duties as officers or directors, other than in cases of fraud or other willful misconduct.

In addition, the Bylaws of the Company provide that the Company is required to indemnify its officers and directors even when indemnification would otherwise be discretionary, and the Company is required to advance expenses to its officers and directors as incurred in connection with proceedings against them for which they may be indemnified. The Company has entered into indemnification agreements with its officers and directors containing provisions that are in some respects broader than the specific indemnification provisions contained in the Delaware general corporation law. The indemnification agreements require the Company to indemnify its officers and directors against liabilities that may arise by reason of their status or service as officers and directors other than for liabilities arising from willful misconduct of a culpable nature, to advance their expenses incurred as a result of any proceeding against them as to which they could be indemnified, and to obtain directors’ and officers’ insurance if available on reasonable terms. The Company has obtained directors’ and officers’ liability insurance in amounts comparable to other companies of the Company’s size and in the Company’s industry. Since a maximum obligation of the Company is not explicitly stated in the Company’s Bylaws or in its indemnification agreements and will depend on the facts and circumstances that arise out of any future claims, the overall maximum amount of the obligations cannot be reasonably estimated.

Legal Proceedings — From time to time, the Company is subject to various claims and legal proceedings that arise in the ordinary course of business. The Company accrues for losses related to litigation when a potential loss is probable and the loss can be reasonably estimated in accordance with FASB requirements. As of March 31, 2020, the Company was not party to any material legal proceedings, thus no loss was probable and no amount was accrued.   

On May 6, 2020, the Company initiated an arbitration proceeding with the Hong Kong International Arbitration Center against SMIC New Technology Research & Development (Shanghai) Corporation (“SMIC”) due to SMIC’s failure to pay fees due to PDF under a series of contracts. The Company seeks to recover the unpaid fees, a declaration requiring SMIC to pay fees under the contracts in the future, and costs associated with bringing the arbitration proceeding.