Introduction.- Output-Input Ratio Efficiency Measures.- Distance Function Efficiency Measures.- Slacks-based Efficiency Measures.- Efficiency Measurement in Special Production Stages.- Special Types of Input and Output Factors.- Special Types of Data.- Changes of Efficiency over Time.- Basic Ideas in Efficiency Measurement for Network Systems.- Basic Two-stage Systems.- General Two-stage Systems.- General Multi-stage Systems.- Parallel Systems.- Hierarchical Systems.- Assembly and Disassembly Systems.- Mixed Systems.- Dynamic Systems.- Epilogue.