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Operations Research Models and Methods
Computation Section
Subunit Do it Yourself
 - OMIE Functions

This page describes user-defined functions provided by add-ins from the Operations Research/Industrial Engineering portion of the site. They are considered in the order they appear on the Add OMIE dialog. Add-ins not mentioned do not provide generally useful functions. For general comments about user-defined functions see the ORMM Functions page.

Economics Functions

Some of the functions in the Economics add-in can be easily extracted while others cannot. The list of functions is shown below, and each function has the prefix E_ or NPW_.

Several of the economics functions compute the simple time value of money functions used in engineering economics or investment analysis courses. These can be easily used outside the data structures created by the add-in. For example the function E_FP(interest, period) has two parameters, the interest rate and period, and computes the future value of a present amount. In textbooks, the function is often represented as (F/P, i, n). Excel has a built-in functions to compute this value, but we provide these functions to more closely agree with the notation of engineering economics texts. Similar functions are E_AF, E_AG, E_AP, E_FA, E_FP, E_PA, E_PF, E_PG, E_PGeo. Generally A stands for a uniform series, G a gradient series, P a present value, F a future value, and Geo a geometric series. These functions can all be copied from the Economics add-in Function module and pasted into the user's VBA module.

Other functions have more complex arguments and may call other functions and subroutines. The functions prefixed with NPW compute the net present worth of a cash flow with and without inflation and with and without the effects of taxes. They are more tied to the data structures of the Economics add-in.

Inventory Functions

The functions in the Inventory add-in cannot be easily extracted because they each call a complicated data analysis subroutine that extracts the individual inventory parameters and variables from input ranges.

The list of functions is shown below, and each function has the prefix Inv_. See the Inventory add-in for a discussion of the purpose and arguments of each function.


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Operations Research Models and Methods
by Paul A. Jensen
Copyright 2004 - All rights reserved