1. A method for root cause analysis of failure of a manufactured product, the method comprising the steps of: a. developing a knowledge model comprising a network of entities related to field of failure and manufacturing attributes of the manufactured product and interconnected in a cause-effect relationship, each entity comprising an instance of a parameter that is related to one of the field of failure and manufacturing attributes; b. converting the knowledge model into a Bayesian network, the Bayesian network comprising one or more nodes, each node representing an entity of the knowledge model along with a corresponding conditional probability of occurrence of the entity; c. selecting one or more parameters and corresponding instances from a set of failure reports d. mapping the one or more parameters and corresponding instances as a set of evidence to the Bayesian network; and e. determining a root cause of failure along with a corresponding conditional probability based on the set of evidence; wherein converting the knowledge model into the Bayesian network comprises associating each entity of the knowledge model with a plurality of states and each of the plurality of states with an objective value attribute; each objective values attribute being associated with one or more values based on historical data and expert constraints using constraint optimization technique.