Tricks and traps of initiating a product line concept in existing products

Many industries are hampered with introducing the product line concept into already existing products. Though appealing, the concept is very difficult to introduce specifically into a legacy environment. All too often the impacts and risks are not considered adequately. This article describes the introduction of a product line approach in Alcatel's S12 Voice Switching System Business Unit. Practical impacts during the introduction are described as well as tricks and traps. The article not only summarizes the key software engineering principles, but also provides empirical evidence and practical techniques on which to build.