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Methodology Standard

ISO 22468:2020
Value Stream Mapping

The international standard for Value Stream Mapping notation and methodology. A practical guide for practitioners, what it means, how to apply it, and how VeSiMy is structured around it.

Note: This guide explains the VSM methodology that ISO 22468:2020 codifies. VeSiMy is structured around these practices. We are not an ISO-accredited certification body and do not offer ISO certification. The standard itself is published by ISO and available for purchase through national standards bodies.

What is ISO 22468:2020?

ISO 22468:2020 is the first international standard specifically for Value Stream Mapping (VSM). Published in November 2020, it establishes a common notation system, terminology, and methodology for VSM so that maps are consistent and interpretable across organizations, countries, and industries.

Before this standard, VSM notation varied between Lean consultants, textbooks, and organizations. The Toyota Production System used specific icons; Mike Rother and John Shook standardized many in "Learning to See" (1998). ISO 22468 formalizes and extends this into a coherent international reference.

The standard covers: icon definitions, map construction methodology, current state analysis, future state design, and the improvement cycle.

Core VSM Concepts the Standard Defines

Process Box

Represents a step where work is performed. Contains cycle time, operators, uptime, and other metrics.

Inventory Triangle

Shows WIP (work in progress) between process steps. A critical indicator of flow problems.

Push Arrow

Material is pushed downstream regardless of downstream demand. Common source of overproduction waste.

Pull/Supermarket

Downstream signals upstream when to produce. Eliminates overproduction and reduces inventory.

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Information Flow

Dashed lines show how information moves through the value stream, orders, schedules, signals.

Kaizen Burst

The starburst/lightning bolt marks an improvement opportunity on the current state map.

Supplier/Customer

Factory icons at the start and end of the map representing the supplier and end customer.

Production Control

The planning/scheduling function that governs how information flows between supplier and production.

Key Metrics in VSM

MetricSymbolDefinitionWhy It Matters
Cycle TimeCTTime to complete one unit of work at a stepIdentifies bottlenecks when compared to Takt Time
Wait TimeWTTime work sits idle between stepsMajor component of non-value-added lead time
Lead TimeLTTotal time from start to finish, CT + WTCustomer-visible measure of process speed
Takt TimeTTAvailable time ÷ customer demand rateThe pace the process must match to satisfy demand
PCEPCEValue-added time ÷ total lead time × 100%Process Cycle Efficiency. Higher is better. <10% is common in many industries.
WIPWIPUnits of work in progress between stepsHigh WIP = poor flow, cash tied up, quality risk
UptimeU%Percentage of scheduled time equipment/process is availableLow uptime magnifies every other constraint
Defect RateD%Percentage of outputs requiring rework or scrapHidden factory, defects consume capacity invisibly

The VSM Process, Current State to Future State

1
Choose a value stream

Select a specific product family or service line. VSM works on a single flow, not the whole business at once.

2
Map the Current State

Walk the process. Record every step, cycle time, wait time, operator count, WIP, defect rate, and information flow. Map what actually happens, not the ideal.

3
Calculate the metrics

Lead time, PCE, takt time, bottleneck identification. These numbers reveal where waste concentrates.

4
Design the Future State

Apply Lean principles: reduce wait time, eliminate non-value-added steps, balance to takt, pull rather than push, standardize the work.

5
Build the improvement plan

Kaizen events, SMED, 5 Why, Standard Work. Specific actions, owners, and timelines that close the gap between current and future state.

6
Implement and measure

Execute the plan. Re-map after implementation. The loop continues, future state becomes the next current state.

How VeSiMy Aligns with ISO 22468:2020

VeSiMy is structured around the methodology ISO 22468:2020 documents. This means:

Standard notation

Process boxes, WIP triangles, push arrows, supermarket icons, kaizen bursts, supplier/customer factory icons, and production control, all per ISO 22468.

Correct metric definitions

Cycle Time, Takt Time, Lead Time, PCE, WIP, and Defect Rate are calculated using the standard definitions, not approximations.

Current → Future → Implement

The workflow follows the full VSM improvement cycle: current state mapping, future state design, and structured improvement planning.

Industry language adaptation

The standard applies across industries. VeSiMy adapts terminology, "cycle time" becomes "appointment duration" in healthcare, "fermentation time" in brewing, while keeping the underlying methodology consistent.

17 CI tools

ISO 22468 focuses on mapping; improvement execution uses Kaizen, 5 Why, Fishbone, SMED, Standard Work, and other Lean tools that complement the VSM methodology.

Not a certification tool

VeSiMy is a practice tool, not a certification body. We do not issue ISO certificates. The standard is available from ISO and national standards bodies.

Apply ISO 22468 in practice

VeSiMy gives you the VSM notation, metrics, CI tools, and AI coaching to run the full improvement cycle, from current state to measurable results.

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