Emergence and emergent properties have been a popular subject in systems of systems design. This work is an extension of Hinton's work on " under-specification ". Even though emergence is a universal phenomenon that can hardly be modeled, there are still attempts to understand, propose solution what is known by non-desired emergent properties in industrial systems design. This paper focuses also on under specification and impact of requirement evolution. Some approaches even appear to be infeasible as in natural systems; however industrial systems are designed following various methods and techniques and the interface to user is often poorly specified and developed. In that respect, interfaces between systems and human are very hard to model as emergent behavior is hardly predicted and hence largely unknown. The paper attempts at characterizing such properties and initiate the debate on a roadmap for such research to support case studies and applications .