Choose which car to buy. Your final deliverable is the actual working DSS. The user interacts with a DSS in two ways. One way is to enter data into the model, possibly to perform a what-if analysis. Data can be entered, and it also needs to be capable of being deleted. Your model should have one sheet in the workbook that is JUST for data entry. Use the capabilities of Excel to make nicely formatted data entry areas, labeled so that their purpose is self-evident. All necessary instructions for data entry should be right there on that data entry page. Build your model so that anyone can use it, not just you. Explain the data entry completely. The other part of the user interface is the output screen. Although there may be plenty of room to put the input and the output on the same worksheet, don’t do it. In real life, the DSS is likely to be input by clerks, and output by management: Two audiences, two interfaces. Play your interface to your audience. Use Excel’s graphic capabilities where appropriate, and make nice-looking, easy to read, and self-explanatory screens. Assume the user has no knowledge of the problem and must be able to understand intuitively what to do by looking at your screen.You will use a third worksheet in your Excel workbook for the model calculations, and a fourth worksheet for any necessary database information. (You do not need a separate database for this exercise. I am referring to the spreadsheet array as a database.)