The business processes for oil and gas production comprise exploration, appraisal, development, production, sales and abandonment. Typically a field has an economic producing life of 15 to 25 years compared to 3 to 7 years to explore, appraise and develop. Production is an important phase in which hydrocarbons are produced and assets are maintained until the economic limit is reached. Oil production from mature fields will continue to deplete while water production increases. Produced water is to be disposed off in an environmental friendly manner meeting regulatory requirements. Artificial lift to supplement the reservoir energy is increasingly needed to sustain production. Facilities are aging and maintenance activities are expected to increase and hence cost in materials, logistics and human resources. The emphasis is to manage the producing assets in the most profitable manner, i.e. maximize the return on investment through improvement in performance and cost reduction over the complete life cycle. Very often it requires application of new technologies to contain the operating costs and increase oil and gas production. An effective, integrated planning system is required to improve the management and control of operational activities in each asset, and to optimize development over the full life cycle of the asset. To this end, the Operations Reference Planning (ORP) concept was developed as an integrated multi-disciplinary business model. It provides a framework system that will allow various future development scenarios to be tested, and to establish a clear understanding of the parameters that will affect return on investment with proper regard for safety and the environment. An ORP has been developed for the Baram field, one of the nine producing fields in the Baram Delta area, offshore Sarawak, Malaysia, operated by PETRONAS Carigali Sdn Bhd (Sarawak Operations). The Baram field, which contains billion barrels of oil initially in place, is one of the largest producing fields in the area. The field came on stream in 1971 and is still producing merrily after almost three decades of production. Furthermore, there is substantial scope for additional development that will prolong the field life well into the new millennium. This paper discusses PETRONAS Carigali Sdn Bhd's (Sarawak Operations) experience in developing the Operations Reference Plan for the Baram field. It highlights the methodology undertaken, organizational and resources requirements, roles and responsibilities of key positions, multi-disciplinary team approach from subsurface to surface, sharing of good practices, production enhancement and cost reduction initiatives to prolong the field economic life.