UML is a standard language used in business modeling for specifying, visualizing and constructing artifact for software and non software systems. It provides the capability to explore the static structure as well as dynamic behaviour of any large and complex software system. It consists of different software design patterns, templates and frameworks with unique diagrams to represent different aspect of software design during its development phase. Model based verification has been a key area to be explored to establish the model consistency and validation formalization. Through massive survey it is found that still the literature is lacking the well formed rules and semantics for UML model verification at the early stages of any software development. This research work emphasises the development of novel techniques for the verification and validation of different UML models. It also focus on automated test case generations using formal semantics based on different pre-established mathematical theories related to graphs. Testing of any software can be broadly classified into three parts: test case generation, test execution and evaluation. Various tools and techniques have already been proposed by many researchers for automation of model verification specifically for object oriented software designs. In this paper authors have summarized and analyzed different approaches and methodologies related to automated verification of UML models and formalization of rules and semantics in order to automate the test case generation and its evaluation.