Ir Shamsul Muhardzi was involved in all fields of Electrical Distribution and Management in Tenaga Nasional Berhad for 22 years, covering planning, design, engineering, procurement, installation, testing, commissioning and maintenance of electrical system up to 33kV. Ir Shamsul's last year in Tenaga Nasional Berhad was as a Customer Service Manager in charge of Customer Service in areas of Selangor and Wilayah Persekutuan. Leaving Tenaga Nasional Berhad in 1999, Ir Shamsul co-founded (Jurutera Perunding Elektrikal dan Mekanikal Kuasa Tenaga Sdn Bhd, an Electrical and Mechanical Consulting Company. Other Business and expertise involvements are in Engineering Services and Trading in Utility Industry, Information Technology, and Telecommunication Industry via shareholdings in IEI Communications Sdn Bhd, Clicks Network Sdn Bhd and Prisma Nikmat Sdn Bhd.