The study examines the efficiency of private sector banks in India with the help of Window DEA (Data Envelopment Analysis) for a period from 2005 to 2017. With a window of three years, the period was divided into 11 windows. The study outcomes show that 59.9% of all private sector banks in India operate at more than 0.9 level of efficiency, and there are only three occasions when banks were operating at the efficiency value between 0.6 to 0.7. Further, the consistency in the efficiency scores of the banks has also been analyzed using an efficiency mapping matrix, and the mean efficiency score of the bank in each window is studied. The score of standard deviation was interpreted accordingly for these banks. Banks that are showing the highest efficiency scores also have a higher variance of efficiency scores. There was no bank identified in the matrix that promises high-efficiency ratings with low variability. The study concludes that the analysis of the efficiency mapping matrix indicates that, as a DMU escalates in the efficiency scores, the standard deviation reflecting the risk in overall efficiency scores also tends to rise. The findings complement the concept of higher risk to higher return or greater efficiency

Abstract
1. Introduction
    1.1. About Indian Banking
2. Literature Review
3. Research Data and Methodology
    3.1. Data Envelopment Analysis
    3.2. Analysis of Window Efficiency Scores
    3.3. Selection of Input and Outputs
4. Empirical Results
5. Conclusion
6. Limitations and Future Directions
References

• Ashish KUMAR(University School of Management Studies, Guru Gobind Singh Indraprastha University)
• Nakul ANAND(University School of Management Studies, Guru Gobind Singh Indraprastha University) Corresponding Author
• Vikas BATRA(Department of Economics, Indra Gandhi University)