Re-using software architecture in legacy transformation projects

Summary form only given, as follows. Software engineers sometimes have to take part in the legacy transformation projects, which are characterized by the complete absence of automated migration tools. In such cases, specialists usually aim at reproducing the original system using the new technologies, without adding any new features. It is common knowledge that it makes sense to keep the functionality as close to the original as possible, because in this case on could use the legacy system as an executable set of requirements. We argue that another, less obvious advantage of "replicating" the old system is re-use of architectural decisions that built in the original legacy system and usually represent an invaluable treasure, because they reflect an implemented understanding of the application domain.