Product Line Feature Typing: Identifying Complexity and Assisting Product Line Development

Product lines encompass baseline and optional feature extensions that distinguish individual products. Managing these products is difficult both from a development and maintenance perspective, because the features' nature frequently differs. Categorizing the types of features can help product designers plan for product line expansion or re-targeting. In this paper we present an evolving model called “feature typing.” Software products have essentially two types of features: functional or vertical features (what the products do) and characteristic or horizontal features (what they have). Horizontal and vertical elements of features affect product development, deployment and support. Replacing, adding, or deleting features at various times of the product life translates into incurred company costs. Purely vertical, purely horizontal, and horizontal/vertical features have unique characteristics that affect development and field support. In all cases, features tend to crosscut the program, so special consideration of feature characteristics helps better product development and deployment.