Ans:• Function-oriented design relies on identifying functions which transform their inputs to create outputs. In most systems, functions share some global system state. • The functional design process involves identifying data transformations in the system, decomposing functions into a hierarchy of sub-functions, describing the operation and interface of each system entity and documenting the flow of control in the system. • Data-flow diagrams are a means of documenting end-to-end data flow through a system. They do not include control information. Structure charts are a way of representing the hierarchical organization of a system. Control may be documented using a program description language (PDL). • Data-flow diagrams can be implemented directly as a set of cooperating sequential processes. Each transform in the data-flow diagram is implemented as a separate process. Alternatively, they can be realized as a number of procedures in a sequential program. • Functional design and object-oriented design usually result in totally different system decompositions. However, the most appropriate design strategy is often a heterogeneous one where both functional and object-oriented approaches are used.