The requirement for working capital and a company's growth are directly related. The company must invest more in inventories and debtors as sales increase. Determining the quantities and makeup of present assets will aid in the smooth operation of the company. Working capital includes a number of key components, including accounts receivable. Credit sales have a direct impact on receivables. An integral component of a market economy that is competitive is the sale of goods on credit. Insofar as a formal financial instrument is not used to formally recognise the debt obligation, credit sales are often done on an open account. Credit extension entails risk and expense. The goal of credit management is to "promote sales and profit until that point is reached" when the return on investment for additional funding of receivables is less than the expense of raising cash to finance that extra credit.