Table of Contents The Company had accounts receivable securitization arrangements totaling $425 at December 31, 2020, of which $250 was drawn. The Company had accounts receivable securitization arrangements totaling $400 at December 31, 2019, of which $350 was drawn. The $100 reduction in the amount drawn resulted in a corresponding reduction in Cash and cash equivalents. In 2020, the Company sold $32 of a certain customer’s receivables in exchange for cash (of which $0 remained outstanding from the customer at December 31, 2020), the proceeds from which are presented in changes in receivables within operating activities in the Statement of Consolidated Cash Flows. The sale of these customer receivables partially offset the maximum funding reduction resulting from the Arconic Inc. Separation Transaction as well as customer concentration limits within the first accounts receivable securitization arrangement. In 2020, the Company sold another customer’s receivables of $149 in exchange for cash (of which $50 remained outstanding from the customer at December 31, 2020), the proceeds from which are presented in changes in receivables within operating activities in the Statement of Consolidated Cash Flows. The sale of these customer receivables was undertaken to offset a change in the customer’s payment patterns (customer had been taking a discount for paying early). The following table details the changes in the allowance for doubtful accounts related to customer receivables and other receivables: At December 31, 2020 and 2019, the portion of inventories valued on a LIFO basis was $458 and $503, respectively. If valued on an average-cost basis, total inventories would have been $131 and $133 higher at December 31, 2020 and 2019, respectively. 88 Other Customer Receivable Sales Allowance for Doubtful Accounts N. Inventories O. Properties, Plants, and Equipment, Net Customer receivables Other receivables 2020 2019 2018 2020 2019 2018 Balance at beginning of year $ 1  $ 1  $ 3  $ 15  $ 15  $ 15  Provision for doubtful accounts 1  2  —  3  7  2  Write off of uncollectible accounts —  (1) (2) (1) (2) (1) Recoveries of prior write-offs —  —  —  (1) (3) (3) Other (1) (1) —  3  (2) 2  Balance at end of year $ 1  $ 1  $ 1  $ 19  $ 15  $ 15  December 31, 2020 2019 Finished goods $ 528  $ 524  Work-in-process 629  741  Purchased raw materials 292  299  Operating supplies 39  43  Total inventories $ 1,488  $ 1,607  December 31, 2020 December 31, 2019 Land and land rights $ 98  $ 99  Structures 1,033  938  Machinery and equipment 3,879  3,626  5,010  4,663  Less: accumulated depreciation and amortization 2,626  2,449  2,384  2,214  Construction work-in-progress 208  415  Properties, plants, and equipment, net $ 2,592  $ 2,629 