Our team ensures everything runs smoothly

Our governance

  • Johan Ballot

    Johan has over 28 years of extensive experience in senior roles within the mining industry, having worked across various commodities and jurisdictions. Leveraging his background in leadership and technical roles, he has a strong ability to unite teams towards common goals, ensuring mine safety, cost control, and meeting production requirements. Johan excels in setting strategic direction and bringing people together to achieve common objectives, leading diverse teams to success.

    With expertise in mining operations management, contract management, health and safety, business development and due diligence (M&A), continuous improvement, and building high-performing teams, Johan creates a collaborative and inclusive work environment. His strategic vision and leadership consistently achieve business objectives, fostering both safety and efficiency in mining operations.

  • Michael Johnston

    As a mechanical engineer, Michael brings 20 years of fleet and plant management experience for both mine owners and operators. He has developed and delivered robust asset strategies, systems and solutions across a number of contracting business for the last 16 years – a driving force in optimising fleet performance, reliability and cost.

    As a natural leader, Michael excels at motivating his teams to identify opportunities to add value by finding faster, smarter, and safer ways of working.

    Michael is passionate about identifying and evaluating the digital innovations and emerging technology of Mining 4.0 and its transformative role in site performance and productivity. In particular, the role automation and predictive analytics plays to shape fleet operations including improving maintenance schedules.

    As General Manager Assets, Michael is responsible for leading and executing Asset Strategy for BUMA Australia.

  • Mel Cunado

    Mel is an accomplished lawyer with over 14 years of expertise developed across roles in top-tier Australian law firms and global contractors with a focus on the construction and resources industry.

    Mel has advised owners and contractors throughout the full contract mining life cycle and, more recently, has led strategic projects focusing on business partnerships, acquisitions and growth.

    Mel uses her deep understanding of the technical, legal, commercial and operational drivers of contract mining to guide her team and stakeholders to manage risks, make informed decisions and pave the way for BUMA’s continued growth.

  • Russell Moon

    Russell is a passionate Safety and Training professional with over 18 years’ experience working in both site-based and corporate leadership roles with both Contractor and Owner teams across the resources industry, including coal, gold, and drilling and completions within Australia.

    He and his team believe that an educated and engaged workforce is a safe and productive one. This belief drives their focus on developing employees, supervisors, and leaders in risk management thinking and application, ensuring the highest standards of safety and effective training practices are achieved.

    As part of his role, Russell is responsible for creating and executing the Health, Safety, and Training strategy across BUMA Australia.

  • Wen Khong

    Wen is a chartered accountant with over 16 years of experience across multiple accounting roles in ASX top 10 listed companies and top-tier international accounting firms with a focus on the mining and resource industry.

    Wen has worked across multiple areas of accounting and finance, with expertise across management accounting, investor relations, forecasting and planning, and auditing. He has a genuine passion for bringing people together and building high-performing teams through continuous improvement.

    As General Manager of Finance, Wen leads the company’s financial strategy, ensuring fiscal health and long-term growth. Wen partners closely with the leadership team to make the right commercial decisions in key matters, and plays a critical role in shaping financial policies and optimising resource allocation.

  • Abbey Mills

    Abbey is an experienced People and Culture leader with over 12 years of experience in driving organisational success across both owner and contractor teams. Having worked with teams across diverse geographical locations including Australia, Indonesia, Canada, and India, Abbey has developed a broad and deep understanding of global workforces.

    Abbey has worked in both on-site and corporate leadership roles and is skilled in driving organisational transformation and system implementations to improve operational efficiency and employee engagement. Abbey is an advocate for a people-centred approach that focuses on collaboration and engagement to foster a high-performing culture.

    As General Manager People & Culture, Abbey is responsible for creating and executing People & Culture strategy across BUMA Australia.

Board of Directors

  • Colin Gilligan

    Colin has 30 years of experience in the resources sector, he has worked across all major mining jurisdictions worldwide throughout his career. Colin has developed and operated mining projects in many commodities including gold, copper, tantalite, lithium, mineral sands, graphite and coal. He has held operational, technical, executive and director roles throughout his career, as an owner and as a mining services provider in private and public companies.

    In his leadership at BUMA, Colin prioritises organisational excellence through people, culture, and efficiency, contributing to establishing BUMA as a prominent participant in the Australian mining industry. His extensive expertise covers operational, technical, governance, funding, risk management, and strategic matters.

  • Ashish Gupta

    Citizen of the Republic of India, born in 1975, domiciled in Singapore.

    Ashish Gupta has been serving as the Commissioner of PT Delta Dunia Makmur Tbk since August 2021. He possesses over 20 years of experience in corporate finance and investing across various industries, including financial services, technology, media, natural resources, and infrastructure.

    He joined Tiga Investments in 2019 as a Managing Director. Prior to this, he served as Managing Director and Partner at Farallon Capital Management from 2007 to 2019, where he played a pivotal role in most of the private credit and private equity investments of Farallon Asia. He began his career as an Investment Banker at Goldman Sachs.

    He obtained a Bachelor of Commerce (Hons) from Shri Ram College of Commerce, New Delhi, and a Post Graduate Diploma in Management from the Indian Institute of Management, Ahmedabad.

  • Ronald Sutardja

    Indonesian citizen, 56 years old, domiciled in Jakarta.

    Ronald Sutardja has been serving as the President Director of PT Delta Dunia Makmur Tbk since August 2021. He brings over a decade of CEO level experience, leading robust transformations in various multi national. He is known for his strategic vision, effective team leadership, and innovation.

    Before assuming his current position, he served as Vice President Director from 2012 and as President Director from 2014 at PT Bukit Makmur Mandiri Utama (BUMA), the subsidiary of PT Delta Dunia Makmur Tbk. His rich career also includes roles as Director at PT Trikomsel Oke Tbk, Head of Field Operations at Northstar Group, positions at Infineum Singapore Pte. Ltd., Michelin Malaysia, and Asia Pacific, as well as Booz, Allen & Hamilton Inc.

    Ronald earned a Bachelor’s Degree in Mechanical Engineering from the University of California at Berkeley, a Master of Science from the Massachusetts Institute of Technology, and a Master of Manufacturing Management from Northwestern University-Kellogg Graduate School of Management.

  • Dian Sofia Andyasuri

    Dian Sofia Andyasuri has been serving as the Director of PT Delta Dunia Makmur Tbk since June 2023. She brings over 22 years of experience from Indonesia, the United Kingdom, and Singapore in various financial roles across several industries, including telecommunications, oil & gas, consulting services, and utility companies.

    Before her tenure with the Company, she held positions at Thames Water, Hutchison, and Shell Indonesia, where she last served as President Director and Country Chair.

    She earned a Bachelor’s degree in Accounting from Trisakti University and a Master’s degree in Finance from Brunel University London.

  • Silfanny Bahar

    Indonesian citizen, 46 years old, domiciled in Jakarta. Silfanny Bahar serves as Director of PT Bukit Makmur Mandiri Utama (BUMA) since May 2023. With over 20 years of professional experience spanning financial analysis, modeling, governance, and assurance, she brings a wealth of expertise to her role.

    Prior to her current position at BUMA, Silfanny spent 11 years at Shell Indonesia, culminating in her role as Finance Director, responsible for financial planning, control, and risk management.

    Silfanny obtained a Bachelor’s Degree in Accounting from University of Indonesia.