A three-tiered language for the specification of micro-architectures is  developed. (i) The structural and invariant properties to be maintained in the collaboration  among the objects in the micro-architecture are specified in the lowest  tier. (ii) The behaviour of the object methods in the classes and the roles of these  objects are specified in the middle tier. (iii) The interactive behaviour of the objects  in the micro-architecture is specified in the third tier of the language. The  specification language is based on Larch and accompanying notations and tools