Modern-day technologies are described by very high-level of computerization, deploying composite and sophisticated machines. The objective behind is to achieve higher productivity and profit in an organization. Therefore it is always desirable to achieve maximum calculated output from every machine in the industry. Reduction in downtime is a step towards getting a maximum output from machines by improving their reliability and availability. In the present research work a systematic approach for Maintenance Planning and Control (as Modified Six Step Method) has been applied on one of the critical Unit, Boiler Section of Thermal Plant as a Case Study. Down time has been reduced by analyzing the failure pattern of critical parts of all types of equipment. The study suggested that with proposed maintenance plan, downtime of a thermal plant can be reduced by 430 hrs over a period of three years and monetary benefit to the organization due to new maintenance policy is of the order of Rs. 18, 00, 00, 000 to 36,00,00,000 INR for the span of three years.