Value Stream Mapping by the Numbers: Lead Time, Process Efficiency & Flow

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Read the data boxes of a current-state value stream map, adjust each cycle time for uptime, spread the changeover over the batch and total the inventory in the stream.
• Calculate the takt time from the available time and customer demand, load every step against it, flag the steps over takt and count the machines each step would need.
• Turn every inventory triangle into days of waiting with Little's law, add them up to the lead time, find where the waiting piles up and size the WIP for a 10-day target.
• Add up the waiting and processing time to the production lead time, separate the value-added seconds and calculate the process cycle efficiency — and see how tiny it is.
• Calculate each step's daily capacity, find the bottleneck with INDEX/MATCH, multiply the first-pass yields into the rolled throughput yield and work out how many units the line must start.
• Size the future-state inventory from lot sizes and buffers, calculate the new lead time and the reduction, and check what the smaller stamping lots mean for changeovers after SMED.
• Turn current and future WIP into days of waiting per inventory point, total both lead times, compare the process cycle efficiency and chart the before/after picture.
• Put a price on the future state: the cash released from inventory, the yearly carrying, scrap and space savings, and the payback of the kaizen in months.