Supply chain disruption remains a major challenge in ramping up production, Pawan Goenka, managing director and chief executive at Mahindra and Mahindra Ltd (M&M), said on Friday. “Demand continues to be robust on strong fundamentals. Our cash collections are good at the moment. We are looking to build inventory for the festive season, but supply constraints remain," Goenka said while reviewing M&M’s June-quarter earnings. M&M, which saw strong recovery in demand for tractors and utility vehicles that are sold largely in the rural and semi-urban markets, could not produce enough to match demand during June and July.