Visit Flux Poussé (Push System) is a production organization model where product manufacturing is triggered upstream, not by real and immediate customer demand, but by a forward planning (based on sales forecasts and stock targets). This is the historical model of the mass production era.
In-depth definition : In a Pulsed Flow system, production is launched according to a predetermined centralized planning, often dictated by the planning department or the’ERP (Enterprise Resource Planning), The products or semi-finished products are “pushed” to the next stage, and then to the finished goods stock, whether or not there is downstream demand. The fundamental assumption is that it is more efficient to produce large batches (economy of scale) in anticipation of future demand. Production orders are created to saturate machine capacity, maximize volumes and minimize tool changeover times, without waiting for a market signal.
The Pushed Flow Cycle and Tools
The operation of a Pulsed Flow system relies on precise tools and concepts:
- Planning (MRP) : The heart of the system is often the MRP (Material Requirements Planning), which calculates material and component requirements to execute the Master Production Plan (MPP), itself based on sales forecasts. This calculation determines the manufacturing orders that will be “pushed” into production.
- Lot size : In order to make machine set-up times more profitable, the Flux Poussé system favours production by large batches. Although this reduces the unit cost of manufacture (thanks to the effect of scale), it significantly increases product transit times and the level of in-process and finished inventory.
- Postal Independence: Each workstation produces at its maximum capacity, or according to schedule, and stores the surplus before passing it on to the next stage. The workstations are disconnected from each other by buffer stocks.
Strategic Risks of the Push Model (Muda and Counter-Performance)
Although historically effective for stable, low-variety markets, Push Flow has major disadvantages in a modern, volatile, customer-centric environment. These disadvantages are directly linked to the seven wastes (Muda) identified by the Lean Management :
- Overstock (most visible Muda): This is the direct consequence of Push Flow. Production based on forecasts generates Buffer stocks important. These inventories are expensive (capital investment, storage space, insurance) and mask process problems.
- Overproduction : The risk of producing items that are ultimately not demanded by the market. Overproduction leads to obsolescence, markdowns and, in the worst case scenario, scrap.
- Waiting time and Cycle length : Products often have to wait until the downstream station has consumed its own buffer stock. This considerably lengthens crossing time (Lead Time), making the company slow and unresponsive.
- Poor Quality : A defect produced in a push-flow process is often not detected until much further down the line. The company may have produced thousands of defective units before the alarm is sounded, resulting in massive non-quality costs.
The Impact on the Supply Chain and the Need for Evolution
For SMEs advised by an engineering consultant, maintaining a purely push-flow system can jeopardize the company's success.’Operational Excellence :
- Market responsiveness: The company is unable to react quickly to peaks or troughs in demand, nor to quickly integrate changes in customer specifications (requiring modifications in the Manufacturing file).
- Financial fixed assets : The excess inventory generated by this system weighs heavily on working capital requirements.
- Visibility : Buffer stocks conceal inefficiencies and Choke bolts making the’Continuous Improvement (KAIZEN) difficult to target.
This is why, in most modern industries, companies are looking to migrate to a more agile and responsive system, the Pulled Flow, This is achieved by using intelligent inventory management software to provide the necessary visibility for this transition. Even if certain processes (such as refining or energy production) remain naturally advanced, the objective of the Industrial Engineering is to isolate this tipping point and apply the principle of Pulled Flow as far upstream as possible, for example by using Kanban or Safety Stock to absorb variability without generating unnecessary overstock.