This review discusses the potential of electrowetting-on-dielectric (EWD) microfluidics for true lab-on-a-chip applications. The paper explores how EWD can enable programmable, reconfigurable, and reusable microfluidic systems that can handle various laboratory protocols. However, this requires a complete set of elemental fluidic components to support all necessary fluidic operations. The paper describes architectural choices and the implementation of biomedical fluidic functions using on-chip electrowetting operations. It also discusses the current status of the EWD toolkit and raises questions about which applications can be performed on a digital microfluidic platform and the advantages of EWD technology, such as reconfigurability. The paper examines the development of lab-on-chip applications in a hierarchical approach. It considers diverse applications in biotechnology as the basis for requirements for electrowetting devices. These applications drive a set of biomedical fluidic functions, such as cell lysing, molecular separation, or analysis. Each fluidic function encompasses elemental operations, such as transport, mixing, or dispensing, which are performed on elemental components like electrode arrays, separation columns, or reservoirs. The paper highlights the challenges in microfluidic system development, including the lack of standard commercial components and the resulting high specialization of microfluidic devices. It emphasizes the need for a hierarchical integrated microfluidic design approach to facilitate scalable design for many biomedical applications. This approach aims to raise the level of abstraction for performance modeling and simulation to the applications level, placing design concepts in the hands of users rather than technologists. The paper also discusses the importance of modularity in the architecture, allowing flexibility in creating and choosing fundamental operations that meet specific user needs. The hierarchical taxonomy includes applications at the top level, microfluidic operations at the second level, and components at the third level. The paper concludes that a versatile architecture capable of accommodating multiple applications requires integrated components on a common substrate and reconfigurable computing and electronic control.This review discusses the potential of electrowetting-on-dielectric (EWD) microfluidics for true lab-on-a-chip applications. The paper explores how EWD can enable programmable, reconfigurable, and reusable microfluidic systems that can handle various laboratory protocols. However, this requires a complete set of elemental fluidic components to support all necessary fluidic operations. The paper describes architectural choices and the implementation of biomedical fluidic functions using on-chip electrowetting operations. It also discusses the current status of the EWD toolkit and raises questions about which applications can be performed on a digital microfluidic platform and the advantages of EWD technology, such as reconfigurability. The paper examines the development of lab-on-chip applications in a hierarchical approach. It considers diverse applications in biotechnology as the basis for requirements for electrowetting devices. These applications drive a set of biomedical fluidic functions, such as cell lysing, molecular separation, or analysis. Each fluidic function encompasses elemental operations, such as transport, mixing, or dispensing, which are performed on elemental components like electrode arrays, separation columns, or reservoirs. The paper highlights the challenges in microfluidic system development, including the lack of standard commercial components and the resulting high specialization of microfluidic devices. It emphasizes the need for a hierarchical integrated microfluidic design approach to facilitate scalable design for many biomedical applications. This approach aims to raise the level of abstraction for performance modeling and simulation to the applications level, placing design concepts in the hands of users rather than technologists. The paper also discusses the importance of modularity in the architecture, allowing flexibility in creating and choosing fundamental operations that meet specific user needs. The hierarchical taxonomy includes applications at the top level, microfluidic operations at the second level, and components at the third level. The paper concludes that a versatile architecture capable of accommodating multiple applications requires integrated components on a common substrate and reconfigurable computing and electronic control.