A colleague offered advice on setting up an Excel spreadsheet which is useful for managing features in a software development project, a.k.a. feature culling. This happens when you are planning for a new project, but you and/or management has to decide what goes in and what doesn't. Open the template and put all features in the feature column. Then play with inclusion of features for each version by entering or deleting the 1. You can immediately see the effect the feature has on the development time.
Here is the template: feature culling.xls
Joel Spolsky offers more insight into planning, with a few helpful Excel tips: