Paper describes the challenges and forward developments to face up on Operation and Maintenance (O&M) issues at the Johan Sverdrup field (Blocks: PL 501, PL 265 and PL 502), on the phases (Concept and Design, Construction and Hook-up, Commissioning, Operations and Maintenance, and Recycling), and a research study of the Oil&Gas profitability. Estimated reserves are between 1.8 billion to 2.8 billion bbl, so assessing the total risk of the field development is crucial. Although, development is estimated to cost up to $31 billion, but the full life-cycle price tag, including operating costs through 2068, is around $58.33 billion. The purpose of this paper is to demonstrate a conceptual methodology analysis framework, for understanding how analysis of cost and benefits, are carry out for assessment and implementation of the Condition Base Monitoring (CBM) and measure the total OPEX (Operate Expenditure/Operating Cost). As well as a specific maintenance philosophy and conceptual approach on the business cases studies of the project lead, to a cost-effective solution. Paper begins by providing a background for analyzing the life-cycle impacts during the life of the field (50 years), and describing measures to implement during the O&M strategies. Follows by targeting the expectations, which one rest on profitability and optimization of the field, with oil prices above $60 per barrel (proved on Case 3). The harvest will, therefore, be profitable even after the price crash. Life Cycle Cost (LCC) analysis (Alternatives A and B) focuses and identifies "Cost Items" (Cost Drivers) that the project carries. Achieved a reliable "concept development" is the greatest ambition, but uncertainties on Maintenance strategies and programs, have showed high cost at early phases. The aim was to measure the actual costs against predicted LCC and to calculate the cumulative costs throughout a product's Life Cycle (LC) of the assets. Discussed and summarized the extent to which these costs and benefits may already take into account and how the CBM strategy mechanism should be works based on a model built. Finally, is demonstrated through calculating an ″downtime scenario″ that could happens, which one creates Deferred Production Costs. Also, has been estimate the cost-benefit analysis (CBA) might be applicable on the researched project development ratio (cost vs. benefit), with overall maintenance effectiveness strategy under study on the LCC Alternative 2. Therefore, describing the maintenance support functionality, based on input obtained from CBM systems and a predictive, periodic maintenance plan is indispensable, in order to cut off potential costs, target future benefits and guaranty a safety robust production installation. At the end, the paper addresses the future performance outlook development in the Oil&Gas Industry as whole, stating essential optimization valuable principles. • Oil&Gas price. • Condition Base Monitoring (CBM). • LCC Analysis. • O&M Cost. • Cost-Benefit Analysis (CBA. [ABSTRACT FROM AUTHOR]