PRP-4: An Updated Version of the Discounted-Cash-Flow Program PRP.

摘要

A previous report described the computer program PRP, which can be used to calculate the production cost (product price) of a product from a process plant when the investments, expenses, interest rates, rate of return on equity, and similar related data are specified. Conversely, if the product price is given in advance, the program can be used to calculate the annual rate of return on equity. The program uses the discounted cash flow procedure in a trial-and-error mode and generates a table showing the annual cash flow history of the project. The purpose of the present report is to bring users of PRP up to date on the current version of the program, which is designated PRP-4. During the period 1977 to 1981, four new options were added to the program to increase its utility: (1) use of escalation or inflation rates for costs and product prices, (2) debt retirement by constant annual principal reduction, (3) use of product price ratios when a plant produces several products, and (4) provision for user-inputted annual tax depreciation percentages. In addition, investment tax credits are now taken in the year of which the investment is made rather than in the year of plant startup. (ERA citation 08:034964)