Lean Operations & Flow Engineering Lab

Value Stream Mapping (VSM) Lab

Calculate Value Stream Mapping (VSM) lead time, Process Cycle Efficiency (PCE), Rolled First Pass Yield (RTY), and Lean Kaizen inventory savings in a free lab.

VSM Model Stage Breakdown Lean Flow Theory FAQ

Lean Pipeline Presets

Load benchmark production value streams.

Step 1: Input Daily Demand, Costs & Multi-Stage Process Parameters

Value Stream Cycle Times, WIP & Yields

Demand & Working Capital Drivers

$
%

Sequential Process Stages (Cycle Time, WIP Queue & Quality Yield)

min
WIP
%
min
WIP
%
min
WIP
%
min
WIP
%
Production Lead Time (PLT)
18.1 days
18.0d queue + 70.0m touch time
Process Cycle Efficiency (PCE)
0.8%
Severe Flow Stagnation
Rolled First Pass Yield (RTY)
90.3%
9.7% cumulative defect loss
Locked WIP Working Capital
$540,000
$108,000/yr inventory carrying drag

Value Stream Mapping Timeline & Stage Flow Audit

Value Stream Stage Touch Time & Inventory Buffer Queue Duration (Days) First Pass Quality Yield

Lean Manufacturing Principles

The Physics of Flow & Waste

Pioneered by Taiichi Ohno and the Toyota Production System (TPS), Value Stream Mapping exposes hidden inventory waste (Muda):

  • Value-Added Time (VAT): The few minutes when human labor or machinery actually transforms the shape, form, or function of the product.
  • Queue Waiting Time: Days or weeks parts sit in inter-stage storage bins awaiting the next batch run.
  • The 95/5 Rule: In un-optimized processes, over 95% of total lead time is pure idle queue delay.

Explore queue dynamics in the Little's Law WIP & Flow Lab.

Mathematical Formulas

Essential Lean VSM formulas

Queue Days = WIP Inventory Units ÷ Daily Customer Demand

Production Lead Time (PLT) = ∑ Queue Days + ( ∑ VAT Minutes ÷ Working Min/Day )

Process Cycle Efficiency (PCE) = ( VAT Days ÷ Production Lead Time ) × 100%

Rolled First Pass Yield (RTY) = Yield_1 × Yield_2 × ... × Yield_n

Annual Holding Drag = ( ∑ WIP Units × Unit Cost ) × Carrying Rate

Balance assembly line pacing in the Takt Time Lab.

FAQ

Value stream mapping & lead time questions

What is Value Stream Mapping (VSM)?

VSM is a Lean management method for analyzing the current state and designing a future state for the series of events that take a product or service from its beginning through to the customer.

How is Production Lead Time (PLT) calculated in a VSM?

Production Lead Time = Total Queue Waiting Days (WIP / Daily Demand) + Total Value-Added Processing Days (VAT / Working Minutes per Day).

What is Process Cycle Efficiency (PCE)?

PCE (or Flow Efficiency) = (Value-Added Time / Production Lead Time) * 100%. In un-optimized batch manufacturing, PCE is typically under 5%, whereas world-class Lean operations achieve 15% to 25%+.

What is Rolled First Pass Yield (RTY)?

Rolled First Pass Yield is the probability that a unit will pass through all sequential process steps without any defects or rework: RTY = Yield1 * Yield2 * ... * YieldN.

How does reducing WIP inventory improve lead time?

According to Little's Law, Lead Time = WIP / Throughput. Eliminating non-value-added queue buffers directly shortens lead time without requiring faster machine processing speeds.

Can I export the VSM lead time and PCE audit to CSV?

Yes. You can export complete stage cycle times, WIP queue counts, lead times, PCE, and Lean Kaizen inventory savings as a UTF-8 CSV spreadsheet with formula injection defense.

Continue Exploring Operations & Quality Tools

Explore our Operations & Quality Hub, model queue physics in the Little's Law Lab, balance line flow in the Takt Time Lab, or calculate batch economics in the EPQ Production Lab.