Maintenance activities conduct to manage and preserve assets integrity. Risk assessment is used to develop interval inspection hence, maintenance strategy can arrange perfectly. On the other hand, prescriptive inspection is still used as the main consideration to determine the inspection schedule. The consequence is an ineffective inspection activity. Past expert judgement was a major consideration in resulting prescriptive schedule which probably has not been reassessed and updated at present. A quantitative assessment can cover the probability and consequence of failure through a detailed assessment. The assessment takes time to be developed which complex systems and formulas are adjusted to the actual condition. Somehow, this task might be conducted by an external party who has expert knowledge. Therefore, within this schedule vacancy, any deterioration might occur in the system. A qualitative assessment can be done to estimate risk. Local engineers, who have basic knowledge of corrosion and other damage factors, can do the qualitative assessment. The result shall update the previous prescriptive methods. In processing qualitative assessment, fuzzy methods are chosen due to their ability to cover linguistic tasks and numerical value. In this paper, fuzzy logic was used to determine the probability of failure of equipment. The result was compared to API 581 RBI assessment. At the latter, risk value from both methods was evaluated to determine the inspection interval. Both types of equipment have close results from inspection interval calculation. Mostly, the inspection interval from the fuzzy method was earlier than RBI methods. From this calculation, the fuzzy results can be used as an estimation for the local engineer's consideration to determine any inspection based on qualitative assessment. If the result compared with an 8-years prescriptive inspection interval, inspection interval from qualitative assessment earlier conducted. It means asset integrity could be maintained more precisely. The equipment is pressure vessels in the utility area to support the boiler system from an Indonesian oil and gas company.
|Journal||IOP Conference Series: Earth and Environmental Science|
|Publication status||Published - 14 Sept 2020|
|Event||2nd Maritime Safety International Conference, MASTIC 2020 - Surabaya, Indonesia|
Duration: 18 Jul 2020 → …