Definition
Material and Information Flow Analysis is the practice of mapping the complete flow of materials and information through a production system — from raw material receipt through all processing steps to finished goods shipment — on a single diagram. The map shows both the physical flow of materials (how parts move through the factory) and the information flow (how production is scheduled, how orders are received, how signals travel between processes). By placing both flows on one document, the method reveals disconnections, delays, and waste that are invisible when material and information are analyzed separately.
Japanese Origin
Mono to jōhō no nagare zu (モノと情報の流れ図) means “material and information flow diagram” — モノ (mono, things/materials), 情報 (jōhō, information), 流れ (nagare, flow), 図 (zu, diagram). This is the term Toyota uses internally. The practice was later introduced to the broader lean community as “value stream mapping” by Mike Rother and John Shook in their 1999 book Learning to See, published by the Lean Enterprise Institute.
History
At Toyota, material and information flow analysis developed as engineers needed a way to see the complete production system rather than just individual processes. Taiichi Ohno emphasized seeing the whole — understanding how materials flow from door to door, how information travels from customer order to production instruction, and where the flow is interrupted by batching, waiting, or excess inventory.
Toyota’s operations management consulting division (OMCD) used material and information flow diagrams as a standard tool for analyzing and improving production systems, both within Toyota’s own plants and at supplier companies. John Shook, who worked at Toyota and later at LEI, helped transfer this practice to Western audiences.
The key insight of the method is that improving individual processes (point kaizen) is insufficient if the overall flow between processes is poor. A factory can have highly efficient individual operations and still have weeks of lead time because materials wait in queues between processes. The material and information flow diagram makes this system-level waste visible.
How It Works
Creating a current-state map:
- Start with the customer — document customer demand: quantities, frequency, delivery requirements
- Walk the physical flow — follow the product from shipping dock back through each process to raw material receipt, recording each process step, its cycle time, changeover time, uptime, batch size, and inventory between processes
- Map the information flow — trace how customer orders enter the system, how production is scheduled, how each process knows what to produce next (MRP, kanban, verbal instruction)
- Calculate the timeline — add the processing times (value-adding time) and the waiting times (non-value-adding time) to compute total lead time versus total value-adding time
Reading the map:
- The ratio of value-adding time to total lead time reveals the efficiency of the flow (often less than 5% in traditional batch-and-queue operations)
- Large inventory triangles between processes indicate flow interruptions
- Information flow that bypasses the physical flow (e.g., central scheduling pushing work to each process independently) reveals push-based production
- Disconnections between information flow and material flow indicate opportunities for pull
Creating a future-state map:
- Define the ideal flow based on customer takt time
- Identify where continuous flow is possible and where supermarkets with pull are needed
- Design the information flow to enable pull — connecting downstream consumption to upstream production through kanban
- Create an implementation plan to move from current state to future state
Common Mistakes
Mapping without walking the flow. The map must be created by physically following the product through the factory, not by interviewing managers in a conference room. The genba walk is what reveals the actual flow versus the assumed flow.
Focusing only on material flow. The information flow is equally important. How production is scheduled, how orders are communicated, and how signals travel between processes are often the root cause of flow problems. A map without information flow is incomplete.
Creating beautiful maps that no one acts on. The purpose of the map is to drive improvement, not to document the current state. A current-state map without a future-state design and an implementation plan is an analysis exercise, not a management tool.
Mapping at too detailed or too broad a level. The map should cover one product family flowing through one value stream, at the process level (not the individual operation level). Mapping the entire factory for all products creates an unreadable document. Mapping individual operations within a single process is too detailed for this tool — that is the domain of the standardized work chart.