In this paper, we have proposed a methodology towards improved business process model redesign based on QoS. We have extended an existing framework that generates an exhaustive space of process models from a set of capability library. The solution space is pruned based on goal and constraints considered thereafter. An algebraic framework is deployed that permits integrated multi-dimensional assessments of QoS factors for choosing path from the reduced space towards derivation of an optimal business process model by comparing the QoS values on both quantitative and qualitative scales. The proposed methodology ensures that while deriving a solution, no possible superior business process model is left out. Further, the designs that do not satisfy the given constraints are eliminated. Eventually, the extended and improved framework provides a comprehensive, both syntactically and semantically correct, consistent and improved business process that adheres to the target business goals and constraints specific to a business house. A use case is used to describe our methodology.