Use the Right Process for the Right Job

I'm in the middle of reading Johanna Rothman's new project management book, Manage It!. Johanna presents the variety of project development processes from waterfall to agile. She gives some detail on which process works well in different circumstances. I have six different saws in my garage. Each works best on different projects. I guess I could cut lumber with my hacksaw, but that wouldn't work well. I could also decide to only work on projects that I can do with my jigsaw, but that's not realistic either. I'll keep all six of my saws. Process is like my saws. You need to use the process that works for the project you are working on. Using the wrong process is like trying to cut pipe with a handsaw.