Lead Time Calculator

Lead time calculations rely on segmenting the workflow into distinct operational phases. The fundamental equations used in this tool include:

1. Supply Lead Time: Determines the time required to source materials.
supply_lead_time = supply_delay + reorder_delay

2. Manufacturing Lead Time (M Lead Time): Tracks internal production stages.
m_lead_time = pre_production + production + post_production

3. Order-to-Delivery Lead Time (O Lead Time): Measures the total elapsed calendar time from initiation to receipt.
o_lead_time = receiving_order - placing_order

Imagine you are managing inventory for a retail boutique and need to figure out your total supply cycle. Your supplier notes a supply delay of 4 days, and your internal administrative reorder delay is 2 days. This gives a supply lead time of 4 + 2 = 6 days. Next, your manufacturing phase requires 1 day of pre-production, 5 days of active production, and 2 days of post-production packaging (m_lead_time = 1 + 5 + 2 = 8 days). Finally, if you place an order on Day 1 and receive it on Day 15, your overall order lead time (o_lead_time) is 14 days. Combining these insights allows you to optimize your reorder points and avoid stockouts.

Buffer for Variability: Always add a small contingency buffer to your supply and production estimates to account for unexpected logistics hiccups or machine downtime.

Audit Regularly: Supply chains evolve. Periodically update your pre-production and transport delay variables to ensure your inventory models remain accurate.