Operations Research (OR) is a topic of academic as well as industrial interest which provides tools for solving complex problems by systematic scientific methods. The subject has industrial and social relevance and have many applications in the current industrial scenario. It has developed with additions to the early stage models and is capable to solve many of the present day industrial problems. The academic curriculum of under the graduate programs in engineering in almost all universities have OR as a core or elective subject. Alto, the MBA of many universities and institutions have OR as a subject. Many academic books are available in OR that treat the subject on different perspectives. Most of them introduces the principles and then directly take an example and show the solution. Some of the books fail to present the step-by-step procedure on examples to reach the solutions. Also, what possible alternate solutions exist, the reasons for that, what are those solutions, etc. are not clearly explained. This makes it difficult for the students to clearly understand the models and exact nature of solutions they provide. The introduction and presentation of different topics in this book are in such a way that every learner will start learning from the basics through sufficient number of examples in each model. Every variation in the models and the problems having different type of solutions are presented in every chapter/section. Sufficient number of examples with all required illustrations are provided to convey the concepts in an efficient manner to the target audience. This approach helps to clarify the concepts and make the students capable to learn the modelling and solving of different difficult problems. The solutions of example problems have been thoroughly checked and verified by the author and by classroom adaptation before publication. They have been verified by software solutions also. The examples are presented in such a way that every step of the solution procedure are well explained to make the concepts concrete. In all the chapters, most of the solved examples are different from that provided in any book and care and precautions have been taken to create examples and exercise that can give specific solution patterns. Contents: 1. Operations Research Basics. 2. Linear Programming Problems. 3. LPP Solution - Simplex Method. 4. Variants of Simplex Method. 5. Duality in LPP. 6. Post Optimality Analysis. 7. Integer Programming Problems. 8. Transportation Problems. 9. Assignment Problems. 10. Sequencing Problems. 11. Replacement Analysis. 12. Decision Theory. 13. Game Theory. 14. Dynamic Programming. 15. Inventory Control. 16. Network Analysis. 17. Queuing Theory. 18. Simulation. About the Author: Dr Bijulal D is currently working as Professor in Department of Mechanical Engineering in the Government Engineering College, Barton Hill, Thiruvananthapuram, Kerala. He has more than 24 years of teaching experience in government engineering colleges in Kerala. Out of this service, he was associated with the College of Engineering Trivandrum, Thiruvananthapuram, Kerala in the capacities as Lecturer (pre-revised Assistant Professor), Associate Professor and Professor for about 20 years. Acquired B.Tech. Degree in Mechanical Engineering from the Calicut University and completed his M.Tech. from IIT Kharagpur in Industrial Engineering and Management. Later, he obtained Ph.D. from IIT Bombay from the interdisciplinary centre - Industrial Engineering and Operations Research based on the research conducted in Supply Chain Management. During the teaching career, most of the time Industrial Engineering related subjects in both UG and PG was handled. The subject taught in every year has Operations Research as one of the subjects in UG or PG including MBA. The non-exhaustive list of other subjects handled include Statistics for Engineering Applications, System Modelling and Simulation, Optimization Techniques, Advanced Operations Research, MIS, etc. The passion for teaching by the author has lead to the preparation of this book in Operations Research in view of making the students to feel ease about the subject. In the professional front, the author is a life member of the ISTE, Senior Member of the Indian Institution of Industrial Engineering (IIIE), and Life Member of the Indian Society of Ergonomics (ISE). Organized one International Conference as the Organizing Secretary in association with the ISE and was part of other three conferences. The association to the IIIE made him to be the Honorary Secretary of the Trivandrum chapter of the IIIE. The author works as the reviewer for many international journals and for the Annual Conferences of the System Dynamic Society, USA continuously for many years from 2009 onward. Dr Bijulal D. is an approved research supervisor under the APJ Abdul Kalam Technological University, Kerala.