Just-in-time delivery

How does Just-in-time delivery work, step by step?

1. 1

   Step 1: Sequence the build, then sequence the factory

   The installation sequence comes first and everything else follows it. The designer and the installation contractor agree the order in which components go into the building - by bay, by core, by floor, by crane radius - and that order becomes the manufacturing and loading sequence in the factory. Components are then identified individually, commonly with a unique mark number carried on the drawing, on the component itself and on the delivery paperwork, so that any load can be reconciled against the position it is going into. Getting this wrong is expensive in a way that is hard to recover from, because a module delivered out of sequence on a project with no laydown has nowhere to go but back onto the road.

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   Step 2: Survey the route and the delivery point

   The logistics manager surveys the route from the factory to the gate and the movement from the gate to the crane. Height restrictions, weight restrictions, turning radii, street furniture, overhead services, parked-car pinch points and the swept path of an articulated vehicle reversing onto the site are all recorded, usually with a physical drive of the route rather than from a desk. Where the route or the load raises anything beyond an ordinary delivery, the haulier and the relevant highway and police authorities determine what permissions and conditions apply. The output is a route plan and a delivery point layout showing exactly where the vehicle stands, where the crane stands, and where the exclusion zone sits.

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   Step 3: Book the slots and hold the gate

   Deliveries are booked into timed slots through a delivery management system, and the slot is treated as an appointment rather than a target. Slots are spaced to the time it genuinely takes to unload, lift and release a vehicle, with the interval taken from the installation rate rather than from optimism - on many projects that means one load at a time and a working assumption of somewhere between two and eight lifts a day depending on the component. A gate marshal controls entry, and vehicles arriving early are held off site at an agreed waiting point rather than queueing on the public highway, which is usually a planning condition as much as a courtesy.

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   Step 4: Call the load forward

   The site calls each load forward when the receiving position is genuinely ready - the previous component landed and released, the bay clear, the connection points accessible, the weather within the crane's working limits. The driver waits at the holding point until called. This single discipline is what separates a working just-in-time operation from a queue of trailers on the street, and it depends on somebody on site having a clear, current view of both the installation face and the vehicles in transit.

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   Step 5: Check on arrival, before the load is broken

   The component is checked against the delivery paperwork and inspected for transit damage before any restraint is released - the mark number, the orientation, the protection, the condition of faces and edges, and the presence and condition of the lifting points. Damage found at this stage is a supplier issue with a photograph and a signature against it. Damage found after the module is in the building is an argument. The check is quick, but it is not optional, and it is recorded.

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   Step 6: Lift straight from the trailer

   The lift is planned and carried out under the appointed person's lift plan, using the lifting points, methods and appliances the designer and the lifting specialist have specified for that component. The vehicle is positioned so the component can be lifted without the load travelling over the cab or over anyone. Nothing about the rigging, the capacity or the configuration is decided at the gate - it is set out in the lift plan for that component before the vehicle is called forward, and the lift supervisor stops the operation if what arrives does not match it.

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   Step 7: Land, connect, release and turn the vehicle round

   The component is landed to the survey, temporarily restrained or propped as the temporary works design requires, and the crane is released only when that restraint is in place. The trailer is cleared of packing and restraint gear, the paperwork is signed, and the vehicle leaves so the next slot can run. Turnaround time is measured, because it is the number that governs how many loads a day the project can absorb.

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   Step 8: Review the day and re-plan the schedule

   At the end of each day the delivery schedule is reconciled against what actually landed, and the following days are re-planned. Missed slots, late loads, damaged components and lost crane hours are logged with their causes, because the pattern in that log is what tells the logistics manager whether the model is working or whether a buffer needs to be introduced. On most projects the schedule is reissued daily and treated as the controlling document for the following morning.