S Chand Operations Research by DS Hira & Prem Kumar Gupta

Operations research, or operational research in British usage, is a discipline that deals with the application of advanced analytical methods to help make better decisions.

Further, the term 'operational analysis' is used in the British (and some British Commonwealth) military, as an intrinsic part of capability development, management and assurance.

In particular, operational analysis forms part of the Combined Operational Effectiveness and Investment Appraisals (COEIA), which support British defence capability acquisition decision-making. It is often considered to be a sub-field of applied mathematics.The terms management science and decision science are sometimes used as synonyms.