Integrasi Fuzzy Bowtie untuk Penilaian Risiko Pipa Bawah Laut

Firamanullah, Hirzi Libna (2026) Integrasi Fuzzy Bowtie untuk Penilaian Risiko Pipa Bawah Laut. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pipa bawah laut merupakan infrastruktur penting dalam sistem transportasi minyak dan gas lepas pantai yang rentan terhadap kegagalan akibat faktor teknis, lingkungan, operasional, dan aktivitas pihak ketiga. Kerusakan pada pipa bawah laut dapat menimbulkan gangguan produksi, kerugian ekonomi, pencemaran lingkungan laut, serta ancaman terhadap keselamatan operasi. Penelitian ini bertujuan untuk mengidentifikasi faktor penyebab kegagalan operasional pipa bawah laut, menganalisis tingkat risiko dan pemetaan konsekuensinya, serta mengembangkan indeks risiko berbasis fuzzy sebagai dasar pengambilan keputusan mitigasi dan inspeksi. Metode yang digunakan adalah integrasi Fault Tree Analysis (FTA), Event Tree Analysis (ETA), dan Fuzzy Bowtie Analysis. FTA digunakan untuk mengidentifikasi akar penyebab kerusakan pipa, ETA digunakan untuk memetakan jalur konsekuensi berdasarkan keberhasilan atau kegagalan safety barrier, sedangkan pendekatan fuzzy digunakan untuk mengakomodasi ketidakpastian penilaian probabilitas dan severity melalui skala linguistik, Triangular Fuzzy Number, dan defuzzifikasi. Hasil FTA menunjukkan bahwa probabilitas top event kerusakan pipa bawah laut adalah sebesar 0,0319055, dengan kontributor utama berupa kegagalan integritas struktur pipa sebesar 53%, gangguan pihak ketiga sebesar 37%, kesalahan proses instalasi sebesar 8%, dan cacat produksi sebesar 2%. Hasil ETA menunjukkan bahwa konsekuensi kegagalan dipengaruhi oleh efektivitas enam safety barrier dan membentuk 64 kombinasi outcome, yang kemudian direpresentasikan ke dalam delapan outcome utama. Pengembangan indeks risiko fuzzy dilakukan melalui dua lapis analisis, yaitu top event × outcome untuk menentukan jalur konsekuensi paling kritis dan basic event × outcome untuk menentukan penyebab dominan melalui 600 kombinasi risiko. Hasil analisis menunjukkan bahwa risiko tertinggi berada pada outcome dengan konsekuensi catastrophic, terutama yang berkaitan dengan tidak dilakukannya inspeksi berkala, korosi, kegagalan gasket, emergency anchoring, scouring, aktivitas jangkar, mooring line crossing, human error, dan kecepatan arus melebihi batas desain. Dengan demikian, indeks risiko berbasis fuzzy dapat digunakan sebagai skor prioritas risiko untuk mendukung risk-based mitigation dan risk-based inspection pada pipa bawah laut.
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Subsea pipelines are critical infrastructure in offshore oil and gas transportation systems and are vulnerable to failure due to technical, environmental, operational, and third-party factors. Damage to subsea pipelines can result in production interruptions, economic losses, marine environmental pollution, and threats to operational safety. This study aims to identify the factors causing operational failures of subsea pipelines, analyze the associated risk levels and consequence mapping, and develop a fuzzy-based risk index to support mitigation and inspection decision-making. The methodology integrates Fault Tree Analysis (FTA), Event Tree Analysis (ETA), and Fuzzy Bowtie Analysis. FTA is employed to identify the root causes of pipeline failures, ETA is used to map consequence pathways based on the success or failure of safety barriers, while the fuzzy approach accommodates uncertainties in probability and severity assessments through linguistic scales, Triangular Fuzzy Numbers (TFNs), and defuzzification. The FTA results indicate that the probability of the top Event, namely subsea pipeline failure, is 0.0319055, with the primary contributors being pipeline structural integrity failure (53%), third-party interference (37%), installation process errors (8%), and manufacturing defects (2%). The ETA results show that the consequences of pipeline failure are influenced by the effectiveness of six safety barriers, resulting in 64 possible outcome combinations that are subsequently represented by eight principal outcomes. The fuzzy risk index was developed through a two-layer analysis: top event × outcome to determine the most critical consequence pathways, and basic event × outcome to identify the dominant causal factors through 600 risk combinations. The Analysis reveals that the highest risk is associated with catastrophic consequence outcomes, particularly those related to the absence of periodic inspections, corrosion, gasket failure, emergency anchoring, scouring, anchor activities, mooring line crossing, human error, and current velocities exceeding the design limit. Therefore, the fuzzy-based risk index can serve as a risk prioritization score to support risk-based mitigation and risk-based inspection for subsea pipeline system.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Pipa Bawah Laut, Analisis Risiko, Fault Tree Analysis, Event Tree Analysis, Fuzzy bowtie. Subsea Pipeline, Risk Analysis, Fault Tree Analysis, Event Tree Analysis, Fuzzy Bowtie
Subjects:	T Technology > T Technology (General) > T174.5 Technology--Risk assessment. T Technology > T Technology (General) > T56.8 Project Management T Technology > TC Hydraulic engineering. Ocean engineering T Technology > TH Building construction > TH6840 Piping installation. Pipefitting
Divisions:	Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38101-(S2) Master Thesis
Depositing User:	Hirzi Libna Firmanullah
Date Deposited:	21 Jul 2026 06:10
Last Modified:	21 Jul 2026 06:21
URI:	http://repository.its.ac.id/id/eprint/136020

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