We also wish to support a kind of role-based or subject-oriented programming style [WB & Johnson 90,. Reenskaug & Anderson 92, Harrison & Ossher 93, ...
Search result URL: www.research.ibm.com 
from the website ...
We use the term multi-dimensional separation of concerns (MDSOC) to refer to flexible and incremental separation, modularization, and integration of software artifacts based on any number of concerns. It overcomes limitations of existing mechanisms by permitting clean separation of multiple, potentially overlapping and interacting concerns simultaneously, with support for on-demand remodularization to encapsulate new concerns at any time.
Realizations of MDSOC can permit incremental identification and encapsulation of concerns, without requiring the use of new languages or formalisms. MDSOC promotes reuse, improves comprehension, reduces the impact of change, eases maintenance and evolution, improves traceability, and opens the door to system refactoring and reengineering. Thus, it addresses some fundamental limitations in software engineering.
See original on c2.com