"Multiple boundaries means the system must be prepared for gradual, fragmented change" #readingToday  

Multiple organizational boundaries also means that the system must be prepared for gradual and fragmented change, where old and new implementations co-exist without preventing the new implementations from making use of their extended capabilities. Existing architectural elements need to be designed with the expectation that later architectural features will be added. Likewise, older implementations need to be easily identified so that legacy behavior can be encapsulated without adversely impacting newer architectural elements. The architecture as a whole must be designed to ease the deployment of architectural elements in a partial, iterative fashion, since it is not possible to force deployment in an orderly manner.