This is an addendum to Steven Toole's tip on Trending. Monthly measurements of utilization (storage, CPU, etc.) can be entered in a spreadsheet. Then, the 'Regression Analysis' function of the spreadsheet can be used to obtain the variables in the formula for a line.
The line can then be graphed to show long-term trends. This trend will only reflect history. To this line, add any known resource requirements for new projects.
About the Author: This tip was written by Maura Stavovy.