The line should never wait for the warehouse.

The process carrying the most weight is feeding the line, on time and in sequence. The visible symptom is a line stoppage for a missing part, but the diagnosis is almost never that material is missing: it is on site and cannot be found, or it reached the point of use in a different order than the line needed.

The typical mistake is treating the three warehouses with the same criterion, and its most common variant is locating by product family or by supplier. Convenient to receive, bad to deliver. What works is locating by movement profile: what gets consumed daily near the point of use, what moves once a month where it is out of the way, and work in process with a place of its own between stages instead of leaning wherever there is room.

Work in process is worth a paragraph, because it causes the most trouble and gets the least attention at design time. It is neither raw material nor finished goods: it is what sits between two stages, enters and leaves repeatedly, and almost never has an assigned place. When it does not, it ends up wherever there is room, which tends to be the aisle feeding the line. The cost appears two processes later, when someone searches for a part that was in plain sight but off the system. Giving it a place of its own between stages, with its own entry and exit criteria, is one of the cheapest interventions and one of the most noticeable, and it requires buying nothing.

The second mistake, more expensive to fix late, is recording traceability at the end of the shift. A lot written down hours after the movement does not allow rebuilding the path when it is needed, and in a plant it is needed more often than anyone plans for.

There is a question worth asking before any of the four steps, and it is where the problem really starts. In many plants the warehouse gets the complaint and the cause is upstream: receipts arriving unannounced and unloaded wherever there is room, production orders that change sequence after the component request is assembled, or a material master that does not match what the line asks for by its working name. None of those three is fixed with racking. They get fixed by putting them on the table with production and purchasing, and that is part of the assessment: if the diagnosis stays inside the warehouse, the improvement lasts until the next change of plan.

What improves at each step. Ordering means separating the three flows, redefining location criteria, fixing the delivery point and sequence to the line, and writing the receiving procedure. Nothing is purchased and searching drops. Equipping adds structure where volume justifies it and management software that says where each lot is and in what state. Mechanizing appears when internal transport between warehouse and line consumes more time than the operation: conveyors that bring material to the point of use without anyone pushing it. Automating is the step where the warehouse connects to the line and the buffer between processes stops depending on someone restocking it in time.

When automation makes sense, specifically in this sector. When the delivery sequence has become demanding enough that sustaining it with manual routes is fragile, or when the intermediate storage between two processes running at different rates has become the place where both processes' problems pile up. At that point a direct connection between warehouse and line stops being an efficiency improvement and becomes what sustains the production plan. Commissioning an automated system is measured in months and is planned together with production, because the line does not stop so the warehouse can reform itself.

A warning about timelines, because in a plant they always come up: the only timeline this site publishes is commissioning an automated system. How long ordering, equipping, or mechanizing takes depends on the size and state of the operation, and we would rather say it that way than give a number that later goes unmet.