What is the difference between cycle time and lead time?

Cycle time is how long one process step takes to complete one unit. Lead time is the total elapsed time from when material enters the value stream until the finished product is delivered, including all the waiting between steps. Lead time is almost always far longer than the sum of cycle times because of queue and inventory delays.

How is takt time used in value stream mapping?

Takt time is the pace of customer demand — available production time divided by customer demand. In a value stream map it serves as the drumbeat the future state should be balanced to. Comparing each process cycle time against takt time reveals which steps are bottlenecks (cycle time above takt) and which have spare capacity.

What is percent complete and accurate (%C&A)?

Percent Complete and Accurate (%C&A) is the proportion of work passed to a downstream process that can be used as-is — without correction, clarification, or addition. It is collected from the customer's (downstream) perspective. Multiplying the %C&A of every step gives the rolled percent complete and accurate, a powerful measure of hidden rework, especially in office and service value streams.

What is the difference between a current-state and a future-state map?

The current-state map documents how the value stream actually works today, with all its waste and delays. The future-state map is the redesigned vision — what the value stream should look like after improvements such as continuous flow, pull systems, and load leveling are applied. Kaizen bursts on the future-state map identify the specific projects needed to bridge the gap.

Engineering·12 min read·August 12, 2025

🗺️ Value Stream Mapping: Seeing the Whole Flow

Q: What is value stream mapping?

Value stream mapping (VSM) is a lean technique that diagrams every step — both material flow and information flow — required to deliver a product or service from raw material to customer. It makes waste visible, especially the waiting and inventory that accumulate between processing steps, and serves as the basis for designing an improved future state.

Learn how to draw current-state and future-state value stream maps — calculating takt time, separating cycle time from lead time, tracking percent complete and accurate, and exposing the waste hidden between processes.

📖Industrial Engineering Reference (Full Access)

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What Is Value Stream Mapping?

Value Stream Mapping (VSM) is one of the most powerful tools in lean. It is a pencil-and-paper (or whiteboard) technique for drawing every step required to bring a product or service from raw material to the customer — including not just the processing steps but the information flow that triggers them and the inventory and waiting that pile up between them. Unlike a standard process flowchart, a VSM puts time and material front and center, making waste impossible to ignore.

Topics covered

value stream mappingVSMcurrent state mapfuture state maptakt timelead timecycle timeprocess cycle efficiencypercent complete and accurateleanflowWIPkaizen burstmaterial and information flowvalue stream