Fortunately, there are only six categories of cost. If you run through these in order, you're unlikely to miss anything. Keep in mind that some costs are one time and others are recurring. For instance, you purchase hardware once but pay maintenance on it every year.

1. Software. This includes all software purchased for the project as well as the ongoing cost of maintenance.
2. Hardware. As with software, include all of the costs and be sure to include maintenance. If you plan to depreciate hardware (or software), gather the total cost and the depreciation amount at each year (for 5-year straight line, it's 20% per year).
3. Personnel. Calculate the number of hours of internal personnel time and multiply that by the fully loaded cost.
4. Consulting. If you hired outside help, here's the place to include it. Don't forget, consultants have a way of returning year after year.
5. Training. How many employees spent how many hours in training? Multiply this by the fully loaded cost. Include items such as trainer time and airfare.
6. Other. The catch-all category. Here's where you come clean about that user conference you plan to attend in Bermuda.

That's it for cost. Gather all the data and place it in the appropriate years in the workbook.