Which department would be most effective in establishing customer requirements for a company's new or expanded business opportunities?

The most effective department in establishing customer requirements for new or expanded business opportunities is typically Marketing and Sales. This department is directly engaged with customers and has the best understanding of their needs, preferences, and expectations. By interacting with customers, conducting market research, and analyzing trends, Marketing and Sales can gather valuable insights that drive product development and innovation.

While Research and Development, Engineering, and Operations contribute significantly to delivering products and services, their primary focus is on the functionality, design, and production processes rather than directly identifying what customers want. Research and Development may play a role in translating customer needs into product specifications, but the initial identification of those needs is often best captured by Marketing and Sales, making them pivotal in establishing clear and actionable customer requirements.