According to the Standish group research on average 45% of a software features are never used and only 20% of features are used always or often. It means that on average you could develop two times simpler product and sell it for the same price. Potentially gains can be even bigger, for the enterprise scale systems two times simpler product often means four times shorter schedules and ten times simpler integration and testing.
There is no other way to discover what features would be actually used, than to ask the real or at least potential customers, preferably after letting them to try some features live. One of the tools for aiding the feature categorization is the Kano model of customer satisfaction.
The Kano model separates features into three broad categories:
1. Must-have, mandatory features.
It is necessary to develop these features just to enter the market. However, once the basic requirement is satisfied, customer almost doesn't care about the further improvement of the feature.
For example, the modern web processor has to contains the spell-checker feature to be sell. However, most customers won't even notice if the spell-checker contains 50 or 200 thousands words
2. Linear or performance features
The better this kind of features is developed, the more customer is satisfied.
For example, the more storage space a file storage server provides, the more customers would be satisfied
3. Excitement or "wow" features
Customer won't be disappointed too much if these features are missing. However, the couple of exciter features can provide great customer satisfaction often adding a price premium to a product.
For example, a built-in e-mail client isn't an indispensable feature for a web browser, but it can really excite some people
Must-have features are required for a product to enter the market and therefore have to be developed as soon as possible. After must-have features are implemented, as many linear features as possible should be implemented, because each of these features increases the customer satisfaction (unless there are already too many of those). Exciter features are to be approached the last, but keep in mind that a couple of exciters can contribute very well to the viral marketing of a product.
What kind of categorization do you use for your products? How often do you re-prioritize your feature list?
Feature Categorization and Customer Satisfaction series: