He has also held academic positions at the University of Melbourne, the Australian National University, and the University of Canberra in Australia, and the Universities of Washington, Richmond and Rhode Island in the USA. He has authored / co-authored twenty-five books on strategic cost management, entrepreneurship, financial accounting, accounting theory and financial modelling, and has over 250 academic and professional papers.

Prof. Ratnatunga also worked as a Chartered Accountant with KPMG and is a consultant for the World Bank. He has undertaken a major consultancy for the Australian Department of Defense in the valuation of strategic capabilities and has valued the brand capabilities of major Telecommunication and IT companies worldwide. He is also a world authority on the business and accounting implications of climate change and carbon trading. He has been awarded the prestigious joint American Accounting Association, AICPA (USA), CIMA (UK) and CMA (Canada) Impact on Management Accounting Practice Award, for a paper published in a refereed academic journal that has the greatest potential impact on Management Accounting Practice.

With over 35 years of experience in the ICT industry, Mr Ratnatunga has inspired the different companies of the DMS Group to reach great heights, with his innovative style of leadership.

During the past three and a half decades he has been instrumental in forging enduring business relationships with elite global companies in the Technology sector including IBM, HP, Oracle, Microsoft, Diebold Nixdorf, Lenovo plus more. This has enabled the DMS Group of companies to pioneer the introduction of cutting edge Computer Technology into emerging markets such as: Sri Lanka, Maldives and Bangladesh.

He continues to focus on expanding DMS Group’s presence in new markets in Asia and the Middle East by constantly pursuing new business ventures and technology initiatives.

Mr. Ratnatunga was a Founder Member of the Computer Society of Sri Lanka and a Charter Member of the Rotary Club of Cinnamon Gardens, where he has held the office of President during the period 1994 / 95. Prior to joining the DMS Group Mr. Ratnatunga served as a Commissioned Officer in the Second Battalion of the Ceylon Light Infantry and subsequently worked for many years as a Senior Systems Analyst at a large data centre. He currently serves as a Board Member of the DMS Group's operations in Sri Lanka, UAE, Singapore & Bangladesh.

He currently heads the finance division of the DMS Group of companies , where he oversees all matters pertaining to financial policy, implementation, compliance and control of finances within the entire DMS group. Mr. Rajendran played a key role in the setting up of the company’s overseas branch network and was instrumental in spearheading the financial and other regulatory functions pertaining to the project, thus paving the way for the successful establishment of the company's overseas operation.

In addition to his accounting background, he has also acquired knowledge in Small Business Management from a study programme conducted by the Canadian Overseas Development Bank in the early 80’s. This has enabled him to implement strategic financial solutions for all the subsidiary companies within the group.

Mr. Rajendran has also served as a member of the education and training committee of the Chartered Institute of Management Accountants (UK), Sri Lanka Division, and served as a Council Member of CIMA, (UK) Sri Lanka division.

He also served as a Rotary District Governor in 2000 / 2001, Sri Lanka and Maldives. He has attended 25 Rotary International Conventions in overseas countries. He was the Implementation Chair for 25 Tsunami affected schools which was reconstructed by Rotary and also was the Chairman of College of Governors. He is also a member of the Rotary Club of Colombo West.

He has also been a Director at the People’s Bank (a large Sri Lanka government owned bank) from April 2015 to November, 2018

He moved to DMS Electronics (DMSE) in 1990 as the Engineering Manager and presided over the growth of DMSE's engineering services as the company transformed from a Microcomputer and Personal Computer company to a fully fledged corporate solutions provider. Today, as Director/General Manager, he oversees a division that focuses on System Infrastructure Software, Managed Services and Networking & Unified Communications.

In his professional life, Mr. Weerasinghe has served as the President of the Computer Society of Sri Lanka (CSSL), Sri Lanka's professional body for IT, in 2003. Prior to being elected President, he served on CSSL's Executive Council for many years holding numerous responsibilities, including the posts of Student Counsellor, Secretary and Vice President. He was closely associated with the National IT Conference and served as the Chair of the Proceedings Committee for a number of years. He has also been a member of the CSSL’s Accreditation Board for the accreditation of Information Technology Degrees under the Seoul Accord and currently functions as its Chairman.

Mr. Weerasinghe also counts wide teaching experience in Engineering, Information Technology, Professional Practice and Customer Service and serves as a visiting lecturer at the University of Moratuwa and the Rajarata University of Sri Lanka. He has served as an elected external member of the Faculty Boards of the Faculty of Engineering and Faculty of Information Technology at the University of Moratuwa and the Faculty of Engineering at the University of Sri Jayawardenapura. He was also a member of the sectoral committee for Information Technology at the Sri Lanka Standards Institute.

Shehan holds a MBA from the University of Nottingham and is an Associate Member of both the Chartered Institute of Management Accountants (CIMA - UK) and Chartered Institute of Marketing (CIM - UK). He is also a Certified Management Accountant (CMA - Australia).