In what scenario would fixed lead times not be applied?

Fixed lead times are not applied when using the Inclusive lead time option because this option allows for variable lead times to be factored into the planning process. The Inclusive lead time option is designed to account for uncertainties and variations that may arise in the supply chain. It enables a more flexible approach where lead times can change based on different factors affecting inventory replenishment, production processes, or supplier performance.

In contrast, the Exclusive and Cumulative options generally rely on fixed parameters, imposing stricter lead time constraints. Thus, they do not incorporate the variability that the Inclusive option does, allowing for a more responsive supply chain management strategy. Low safety stock levels are more related to inventory management practices rather than directly affecting the application of lead times. This reinforces why the Inclusive lead time stands out as the scenario where fixed lead times wouldn't be enforced, as it embraces adaptability in supply chain planning.