The literature in requirements engineering recognizes the product scoping
activity as an important source of risks and fails in bespoke software
projects. In order to help address this activity, we designed and implemented
an interactive visual instrument that allows providers and customers to jointly
define the scope of bespoke software products, particularly, information
systems. The instrument was formally evaluated through a qualitative study that
involved three projects in Chile and three in Brazil. Real customers and
providers took part in these experiences. The evaluation results were highly
encouraging, showing the instrument is a serious candidate to help deal with
the product scoping challenges. Customers, software providers and also software
engineering researchers can also take advantage of it, by reusing and adjusting
the instrument to their own reality.