The two main principles of lean manufacturing are ______?

• A. Just-in-time and high volume production
• B. Centralization of control and standardized work
• C. Maximizing output and reducing costs
• D. Responsiveness to change and minimization of waste

Answer: (D)

Two fundamental ideas in lean manufacturing are reducing waste and staying responsive to change. Lean aims to deliver maximum value to the customer by eliminating activities that do not add value—such as overproduction, inventory, waiting, defects, unnecessary motion, and extra processing. By stripping away these wastes, the process uses resources more efficiently and creates smoother flow.

Being responsive to change means the system can adapt quickly to shifts in customer demand, product mix, or market conditions. This involves flexible, pull-based production, shorter lead times, and arrangements that support rapid changeovers and continuous improvement. When a process is easy to adjust and tightly aligned with actual demand, it minimizes buildup of unused capacity and inventory, which are classic wastes lean seeks to avoid.

The other options mix in elements that aren’t central lean principles as a pair. Just-in-time is a common tool within lean, but “high volume production” isn’t itself a defining lean principle. Centralization of control conflicts with lean’s emphasis on flow and empowerment, and aiming to maximize output while cutting costs can overlook the crucial focus on waste and adaptability.