The aim of this book is to develop a generic software architecture for workflow management systems. In this generic model, workflos are described formally in order to deal with their correctness. The correctness is defined in terms of the process definition, and its concrete execution withn a enterprise. the execution of a workflow depends on the availability of the enterprise resources. The modelling approach then includes a generic mechanism that deals with the enterprise resource management. this makes its possible to support the analysis of the differences between the descriptive and the prescriptive model of a workflow. The dscriptive model defines the analogy between business and computing and concentrates on the process level, on one hand the prescriptive model describes the purpose of each process.The generic models defined in the book present suitable abstraction that can be applied at both levels. The methodology presented in this book is based on domain engineering, and on algebraic methods. The main focus of our methodology is based on the enterprise human resource management which plays an important role in the correctness of workflows within an organization.