An integrated framework for maintenance optimisation with petroleum industry.

Maintenance concerns abound as companies strive to increase production while guaranteeing safety, flow assurance and equipment reliability. Therefore, optimisation of the maintenance process is essential to increasing the productivity of the equipment as well as decreasing the maintenance expenditure. Thus, this research is aimed at proposing an integrated framework to optimise the major maintenance activities at strategic and operational levels including spare parts control and risk assessment within the petroleum industry.In this research, the selection of the maintenance optimum policy for equipment within petroleum industry is dealt with at strategic level through multi criteria decision making techniques (classic and fuzzy analytic hierarchy process FAHP). At the operational level, a cost optimisation mathematical model is proposed to balance the costs of failure of a unit during operation against the cost of preventive maintenance to ensure preventive maintenance activities are kept at minimum possible cost without compromising the utilisation of equipment's performance.Furthermore, an integrated approach between spare parts management and preventive maintenance activities is developed to create a cost effective method and ensuring the availability of parts in the stock while carrying out preventive maintenance. A risk assessment model for equipment within the petroleum industry is developed to handle the likelihood of risk and its consequences. A mathematical equation is developed to predict the likelihood of risks and identify the optimum inspection interval. In addition, set of modified mathematical equations to evaluate consequences of risk and weighing the severity of risks in specific areas is developed.The findings of this research indicate that the proposed FAHP will clearly guide the practitioners in selecting the optimum maintenance policies at strategic level by the consideration of the related criteria and the possible alternatives for petroleum equipment. The results from the proposed mathematical model for scheduling preventive maintenance activities showed promising results in terms of cost effectiveness, reliability and availability of equipment without compromising the Inherent safety of the equipment. The integration between preventive maintenance intervals and the control of spare parts provided the petroleum companies with predictable movement of parts at the right time and hence minimises the cost of inventory. The developed equation for the consequences of risk can be used to evaluate the level of risk under different combination of sets of weight which suit the situation under consideration.