In an increasingly competitive industrial context, the management of logistics flows has become a major strategic lever. Two models are traditionally set against each other: the push flow and the pull flow. Understanding their differences, advantages and limitations is essential to optimise the supply chain et renforcer l’ operational excellence of your company.
It is important to support manufacturers in choosing and implementing the flow model best suited to their strategy, while integrating the principles of lean manufacturing and on the Operational performance.
What is a push flow?
The push flow (or push system) is based on a forward planning. Production is launched upstream on the basis of a demand forecasting, often based on historical data or market trends.
Example : A factory produces 10 000 units of a component in January, anticipating demand in March.
Advantages :
- Better use of production capacity (high utilisation rate).
- Lower unit costs thanks to large batches.
- Suited to stable products with highly predictable demand.
Drawbacks :
- Risk of overproduction (one of the 7 wastes of Lean).
- Accumulation of intermediate stocks.
- Less responsiveness to changes in demand.
This model is common in highly seasonal industries or in environments where production is long and costly to launch.
And the pull flow?
The pull flow (pull system), inspired by the Toyota system, operates on the principle of just-in-time. Production is triggered by an actual order, not by a forecast.
Example : A part is only manufactured when a customer places an order or a downstream workstation needs it.
Advantages :
- Drastic reduction in stock levels and tied-up capital.
- Less waste (quality, obsolescence).
- Plus de flexibility and responsiveness.
Drawbacks :
- Requires fine-tuned planning and close collaboration with suppliers.
- Less suited to unexpected demand peaks.
- Depends on a robust information system (ERP, MES).
The Kanban is one of the most emblematic tools of the pull system: cards or visual signals indicate when to replenish a workstation.
The ideal synergy: a hybrid system
In practice, high-performing companies often combine both approaches:
- Flux poussé upstream, for raw materials or standardised components.
- Flux tiré downstream, for final assembly or customisation.
This is what is known as a heijunka system (production levelling), which makes it possible to stabilise flows while remaining responsive.
The bottleneck: enemy no. 1 of flow
Whichever model is chosen, the bottleneck remains a major obstacle to flow. It is a process step whose capacity is lower than demand, thereby limiting overall throughput.
Example : A machine capable of producing 100 parts/hour while the line can process 150.
To identify a bottleneck, use:
- Thecapacity analysis of each workstation.
- The bottleneck calculation (cycle time / maximum cycle time).
- numerous dashboards KPIs (OEE, throughput rate, downtime).
Use the Value stream mapping (VSM) to visualise flows, detect bottlenecks and propose solutions to optimise your operational excellence.
Case study: transition from a push system to a partial pull system
An electrical equipment company was suffering delivery delays despite high stock levels. Our audit revealed:
- An overproduction of 30 % on certain components.
- An bottleneck on the final test line.
- An supply chain with poor responsiveness.
We implemented:
- An Kanban system between assembly and stock.
- An project planning redesigned with smaller batches.
- An automation of the logistics flow thanks to an MES.
Result: stock reduced by 45 %, OEE improved by 22 %, and delivery times cut by 30 %.
Link with the industrialisation of a product
The design of a new product is the key moment to integrate the right flows. Theindustrialisation of a product must include:
- The definition of the industrial process.
- The choice between push or pull system depending on the strategy.
- The drafting of a technical specification document that is precise.
- The validation industrielle of the process.
An manufacturing file , when well structured, makes it possible to standardise production from the outset, avoiding costly corrections along the way.
Discover our article « How to write an effective technical specification document? ».
Conclusion
The choice between push flow and pull flow is not a question of fashion, but of industrial strategy. It must align with the nature of demand, the complexity of the product, et la maturity of the organisation.
By combining the strengths of both models, eliminating bottlenecks, and by relying on a well-managed supply chain, companies can achieve a level ofoperational excellence sustainable.
Xavier Schuster
Consultant at SXE Consulting. Industrial consulting firm based in Luxembourg, 25 years of experience in operational excellence.
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