Which manufacturing approach is characterized by producing items to stock in advance?

The manufacturing approach characterized by producing items to stock in advance is Make-to-Stock (MTS). This method involves creating products based on anticipated demand and storing them in inventory until they are sold. The essence of MTS is to ensure that products are readily available for customers without the need to wait for them to be manufactured.

In MTS, the production process is driven by forecasts and historical sales data, which allows manufacturers to maintain sufficient inventory levels to meet customer demand promptly. This approach is particularly effective in scenarios where demand can be predicted with reasonable accuracy, enabling companies to offer shorter lead times and improve customer satisfaction.

In contrast, the other approaches focus more on customer-specific requirements rather than pre-emptive inventory production. Make-to-Order (MTO) only produces goods after an order is received, Engineer-to-Order (ETO) involves significant customization according to specifications provided by customers, and Assemble-to-Order (ATO) allows for some customization but relies on pre-manufactured components that are assembled only upon receiving a customer order. Therefore, MTS stands out as the correct answer since it directly aligns with the concept of producing items in advance for stock.