INTEGRATED ISHIKAWA DIAGRAM WITH ANALYSIS HIERARCHY PROCESS (AHP): A CASE STUDY OF VARIABLE FREQUENCY DRIVE (VFD) AT HIGH PRESSURE GRINDING ROLL (HPGR) PLANT CONCENTRATING DIVISION PT FREEPORT INDONESIA

• Main Author: Johnli Rio D Burami, Cahyo
• Format: Theses
• Language: Indonesia
• Subjects: Manajemen umum
• Online Access: https://digilib.itb.ac.id/gdl/view/81393
• Institution: Institut Teknologi Bandung

This research provides a framework for addressing challenges in the application of variable frequency drives (VFDs) at the high pressure grinding roll (HPGR) plant of PT Freeport Indonesia (PTFI), specifically within the concentrating division. The division faces significant challenges in operating VFDs, primarily due to recurrent failures that have significantly increased maintenance costs from 2021 to 2023. Consequently, there is a critical need to identify the causes of these failures and to devise effective solutions to mitigate these issues. A comprehensive approach combining qualitative and quantitative methodologies was employed in this study. The research utilized an Ishikawa diagram to visualize the causes of failures, followed by the Analytic Hierarchy Process (AHP) to quantify the identified causes. Integrating AHP with the Ishikawa diagram provided quantification, thereby assigning values to the most contributory factors to VFD failures. This integration revealed that four out of eighteen factors; dust accumulation, use of old spare parts, high humidity, and lack of knowledge were the most influential in VFD failures. To prioritize which issues to focus on for subsequent improvements, this research applied the Pareto principle to demonstrate the percentage of effort made and the outcomes or resolutions achieved. Additionally, a cost-benefit analysis (CBA) was conducted to evaluate alternative solutions, ensuring cost-effective implementation of these solutions. The study demonstrates that implementing recommended improvements; sealing MCC room, install dehumidifier, enhancing storage condition and onsite training for the four highest contributing causal factors has the potential to reduce total maintenance costs by 53.7%.