If you are new to product line practice, you may find  the following reports useful:

• Formulation of a Production Strategy for a Software Product Line
  (August 2009) explains how best to formulate a production strategy for a software product line.
• Product Line Acquisition in a DoD Organization—Guidance for Decision Makers (March 2006) shows program managers the benefits of a product line approach and also provides alternate acquisition approaches for product line capabilities.
• Product Line Adoption in a CMMI Environment (July 2005) addresses product line adoption issues present in the context of an organization already using CMMI for process improvement efforts.
• The Structured Intuitive Model for Product Line Economics (SIMPLE) (February 2005) lays out the details of the SIMPLE model, which can help estimate the costs and benefits for product line development organizations.
• Software Process Improvement and Product Line Practice: Building on Your Process Improvement Infrastructure (September 2004) shows how a process improvement framework can effectively build a foundation for product line adoption.
• Software Product Line Adoption Roadmap (September 2004) provides an overview of phased product line adoption, a strategy that can reduce risk and cut costs.
• Measures for Software Product Lines (October 2003) contains guidance for those who provide measurement activities within software product line practice.
• Predicting When Product Line Investment Pays (July 2003) defines key factors to consider in taking an incremental approach to fielding a software product line.
• Guidelines for Developing a Product Line Production Plan (June 2002) not only provides guidelines for product line production plan development, but also includes strategies for the plan's use and evaluation.
• Software Process Improvement and Product Line Practice: CMMI and the Framework for Software Product Line Practice (July 2002) describes the ways in which organizations can build upon their process improvement efforts to achieve success with software product lines, and realize additional benefits through the use of both technologies.
• Control Channel Toolkit: A Software Product Line Case Study (October 2001) shows the measurable benefits already realized in the use of the toolkit on a space command-and-control system.
• Product Line Analysis: A Practical Introduction (April 2001) introduces software product line analysis in the context of software product line development.
• Basic Concepts of Product Line Practice for the DoD (February 2000) provides fundamental information about software product line practices for the Department of Defense.
• A Case Study in Successful Product Line Development (September 1996) details the product line implementation experience of Swedish company CelsiusTech Systems AB and the benefits realized from a product line approach.