Hero Honda, the country's largest two-wheeler maker, is planning to invest an additional Rs 150 crore in the current fiscal to scale up capacity at the company's new facility here that was inaugurated today.The plant would have an initial installed capacity of half a million bikes per year, which would be increased to a million units by 2008.The company has so far invested Rs 450 crore in the plant. It had announced last year that along with its ancillaries, a total investment of Rs 1,900 crore would be made in the project, which would have an overall production of 1.5 million units by 2010."The plant sets new benchmarks in terms of layout, processes, supply chain management, human resource management, and, most importantly, environmental consciousness," Pawan Munjal, managing director, Hero Honda Motors, said here.The initial production level of the new plant would be 2,000 vehicles per day, which would be ramped up to 4,000 units a day by the end of this year, he added.