Variations in finished products in a manufacturing process are inevitable. It remains in the products even after every effort is made to get rid of it. Thus, variation, to a certain level, is allowed to remain in the system. However, this can be minimized by learning the causes. Control charts are the graphical tools to determine the variations that are present in the product. Microsoft Excel, one of the popular spread sheet programs for data analysis, does not have any option to draw control charts directly. However, it can be drawn following some complex steps and making some adjustments in the in-built graphs of Microsoft Excel. This paper introduces an Excel Add-In program, developed using Visual Basic for Application, for drawing control charts. One can draw control charts directly using this Add-In. This Add-In shall be useful in the field of production and manufacturing for detection of variations during the process of manufacturing products.

Excel Add-In is a software program that extends the basic capabilities of Microsoft Excel. Generally speaking, an Add-In is a program that is added to software to give it additional functionality (Walkenbach, 2009). With Excel Add-Ins, one can integrate additional functionality into Microsoft Excel. One can create an Add-In and use it to add user defined functions, custom dialog boxes, introduce sub-procedures, and custom ribbon tabs to workbooks. Add-Ins are a great way to integrate procedures into any Excel workbook (Etheridge, 2010). Microsoft Excel comes bundled with a number of in-built functions. But often these functions do not meet all the computing needs of the users, and one needs to go through a number of complex steps to do the required computations. Microsoft Office package also comes with a robust programming language called Visual Basic for Applications (VBA) that can be used to automate all the steps one does manually to perform the computations. VBA is a full-fledged programming language built into Excel (and all other Microsoft Office applications), which supports variables (a place to store data) and programming logic (Ferry, 2011). The users can write custom functions using VBA to complement the in-built functions in Microsoft Excel.

In Excel Add-Ins, developed using VBA, the workbook and charts are hidden from the user. Its functions modules can be viewed from the Visual Basic Editor (VBE). However, one can develop a compiled Add-In (.dll and .exe files) using programming language like C++, Visual Basics, etc. These types of Add-Ins are called Component Object Model (COM) Add-In. In Excel 2003, Microsoft has further extended the concept and simplified the implementation of COM Add-In mechanism, so their function could be used in the same way as worksheet functions and VBA user defined functions (Green et al., 2008). These types of Add-Ins are called Automation Add-Ins.

Operations Management Journal, Developing, Microsoft Excel, Visual Basic, Visual Basic for Applications (VBA), Component Object Model (COM), Visual Basic Editor (VBE), Statistical Process Control (SPC), Application, Drawing Control Charts.