Final answer:
The Just-in-Time (JIT) strategy offers the fastest lead time for customers, as it ensures parts are delivered exactly when needed, thus enhancing quality control and efficiency in the production process.
Step-by-step explanation:
The planning strategy that provides the fastest lead time for customers is a) Just-in-Time (JIT). Just-in-Time delivery involves having parts delivered exactly when they are needed in the production process, which eliminates the need for storing them in warehouses. This strategy was notably adopted by American car manufacturers in the 1980s from Japanese business innovations. With JIT, quality control is improved because issues with parts become evident immediately, preventing large-scale defects. It also implies that suppliers must be located within a one-day drive to the main assembly plant for timely delivery, contributing to local economy changes, such as the establishment of parts factories in small towns and competitive pressure on wages due to the need for low-cost, non-union labor.