Computation Section
Subunit Inventory Analysis

The Inventory add-in provides three kinds of functions: deterministic, stochastic and work in progress. All have the prefix "INV_" and appear on the user defined function list. The functions are used in the data forms constructed by the add-in to compute results concerning inventory systems. They may also be used outside the constructs of the add-in on worksheets entirely constructed by the user.

Although some of the results associated with inventories can be calculated with simple Excel formulas, we provide functions that are very general. For example, the same function computes the average inventory level for all kinds of inventories ranging from the simplest deterministic inventory with no shortages to stochastic inventories with lost sales. The function knows which result to compute by the data presented to it.

Most of the functions are stand-alone in the sense that most do not require as inputs the results of any other function. As long as the user provides data in the correct order, the function can be used directly on any Excel workbook.

It is possible to extract the add-ins into a different workbook, but it is made somewhat difficult because the functions in their internal coding use the results of other functions and subroutines in the Inventory add-in. All the functions related to deterministic and stochastic inventories are located on a single VBA module called function_mod. If this entire module is copied to the VBA code of another workbook, the functions become available to that workbook. Similarly, the functions related to work in progress are on the module function_other_mod.

The easiest way to use the functions is to have the Inventory add-in installed. The functions are then all available to all open workbooks.

The three kinds of functions are described on separate pages. To reach these pages click the links at the left or below.

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Operations Management / Industrial Engineering
by Paul A. Jensen
Copyright 2004 - All rights reserved