An automobile factory logistics director review: from the pallet quantity miscalculation to the system optimisation of the actual combat manual

As the logistics director of an auto parts factory, I had paid a terrible price for pallet planning mistakes - the engine assembly line was stopped 3 times per hour due to insufficient number of pallets, resulting in a monthly loss of more than a million. After three years of iteration, we summarised this set ofCalculation of the number of pallets → scientific selection → system optimisationA hands-on guide to successfully increasing conveyance efficiency by 40%. the following are solutions for key scenarios:

​I. Pain point scenarios: the three major disaster scenes of pallet quantity miscalculation​

​Scenario 1: Engine assembly line blockage incident​

• ​issues: Insufficient buffer capacity of pallets, resulting in imbalance between welding and painting processes and accumulation of semi-finished products blocking the aisles.
• ​root cause: Calculation of pallet volumes based on average daily production only, not taking into accountProcess cycle time difference(120 seconds for welding/90 seconds for painting)
• ​prescription::
  ​Dynamic buffer formula::Number of buffer trays = (Longest process cycle - Shortest process cycle) × Output per unit time
  → Additional pallets are required for the production line:(120-90)/60 × 60 pallets/hour = 30 pallets

​Scenario 2: Overloaded and burnt out accident of the doubler chain​

• ​issuesOverloading of cylinder block pallets with a total weight of 200kg led to motor burnout and line down for 8 hours.
• ​root cause: IgnoreLine Load Equation::Maximum number of pallets per section = wire rated load ÷ total weight per pallet
  

  Line Type	Rated load (kg)	Applicable Scenarios
  Synchronous belt conveyor line	≤60	electronic component
  Flat Belt Conveyor Line	≤250	Small and medium-sized machined parts
  ​Speed Chain Conveyor Line​	​≤4000​	​Heavy Duty Vehicle Components​

​Scenario 3: Cold Chain Warehouse Pallets Brittle and Cracked​

• ​issues:: Brittle cracking of ordinary plastic pallets in -25°C environment, loss of cold chain medicines due to collapse of goods
• ​root cause: not matchedEnvironmental adaptation parameters::
  • Cold-resistant HDPE pallets: brittle cracking temperature ≤ -30°C
  • Anti-skid surface design: Friction coefficient ≥ 0.4 to prevent frost and slipping.

​II. Three keys for calculating the number of pallets​

​Key 1: Space Loading Formula - Cracking Waste of Warehouse Area​
​Core formula::Total Pallets = Average Daily Production ÷ (Cartons per Pallet × Stacking Levels)

• ​The number of stacked layers is taken as a minimum::

  make a copy of
  Packaging compression limit = Compressive strength of single box (kg) ÷ Gross weight of single box (kg)
  Pallet pressure limit = pallet dynamic load (kg) ÷ (number of boxes per layer × gross weight per box)  
  ​case (law): Gearbox case weight 25kg per case, compressive strength 200kg → theoretical stacking 8 layers
  
  However, the dynamic load of Tianzhi pallet is only 1.5 tonnes → actual stacking: 1500 ÷ (16 boxes/layer × 25kg) = 3.75 layers →Rounding up to 3 levels​

​Key 2: Dynamic turnover formula - coping with production fluctuations​

• ​Buffer calculation formula::Buffer = (Peak Hourly Output - Average Hourly Output) × Replenishment Cycles
  ​real-world parameters::
  • Peak output: 120 trays/hour (daily 80 trays/hour)
  • Vendor replenishment cycle time: 2 hours
    → buffer minimum tray size:(120-80) x 2 = 80 pallets

​Key 3: Device Compatibility Formula - Avoiding Automation System Conflicts​

• ​Stacker pickup adaptation rules::

  make a copy of
  Fork hole width ≥ 250mm
  Fork hole height ≥ 120mm
  Difference in height of pier foot ≤ 5mm [1](@ref)  
  ​Nine feet of blister tray actual testPass rate of 100% for long side vs 38% for short side.

​III. Four-dimensional matching matrix for pallet selection​

​IV. Five efficiency strategies for system optimisation​

​Strategy 1: Unitised layout to compress handling distances​

• Breaking down a 50 metre production line into5 independent units, per unit configuration:
  • Dedicated tray cache rack (capacity 10 trays)
  • Operating stations within a 3 metre radius
    → Employee walking distance for picking up materials reduced from 15 metres to ≤2 metres, saving 2.7 hours of working time per day

​Strategy 2: Intelligent buffer table to crack the process beat difference​

Image Code
graph LR
Paint line - full pallet conveyor->Lift Table [3layer buffer table] - on-demand feeding -->assembly line  
#svgGraph12817380037229{font-family: "trebuchet ms",verdana,arial,sans-serif;font-size:16px;fill:#333;}@keyframes edge- animation-frame{from{stroke-dashoffset:0;}}@keyframes dash{to{stroke-dashoffset:0;}}#svgGraph12817380037229 .edge-animation-slow {stroke-dasharray:9,5!important;stroke-dashoffset:900;animation:dash 50s linear infinite;stroke-linecap:round;} #svgGraph12817380037229 .edge-animation-fast{stroke-dasharray:9,5!important;stroke-dashoffset:900;animation:dash 20s linear infinite;stroke-linecap:round;}#svgGraph12817380037229 .error-icon{fill:#552222;}#svgGraph12817380037229 .error-text{ fill:#552222;stroke:#552222;}#svgGraph12817380037229 .edge-thickness-normal{stroke-width:1px;} #svgGraph12817380037229 .edge-thickness-thick{stroke-width:3.5px;}#svgGraph12817380037229 .edge-pattern-solid{stroke- dasharray:0;}#svgGraph12817380037229 .edge-thickness-invisible{stroke-width:0;fill:none;}#svgGraph12817380037229 .edge- pattern-dashed{stroke-dasharray:3;}#svgGraph12817380037229 .edge-pattern-dotted{stroke-dasharray:2;}#svgGraph12817380037229 .marker{fill:#333333;stroke:#333333;}#svgGraph12817380037229 .marker.cross{stroke:#333333;} #svgGraph12817380037229 svg{font-family: "trebuchet ms",verdana,arial,sans-serif;font-size:16px;}#svgGraph12817380037229 p{ margin:0;}#svgGraph12817380037229 .label{font-family: "trebuchet ms",verdana,arial,sans-serif;color:#333;} #svgGraph12817380037229 .cluster-label text{fill:#333;}#svgGraph12817380037229 .cluster-label span{color:#333;} #svgGraph12817380037229 .cluster-label span p{background-colour:transparent;}#svgGraph12817380037229 .label text, #svgGraph12817380037229 span{fill:#333;color:#333;}#svgGraph12817380037229 .node rect,#svgGraph12817380037229 . node circle,#svgGraph12817380037229 .node ellipse,#svgGraph12817380037229 .node polygon,#svgGraph12817380037229 .node path{ fill:#ECECFF;stroke:#9370DB;stroke-width:1px;}#svgGraph12817380037229 .rough-node .label text,#svgGraph12817380037229 .node .label text,#svgGraph12817380037229 .image-shape .label,#svgGraph12817380037229 .icon-shape .label{text-anchor:middle;} #svgGraph12817380037229 .node .katex path{fill:#000;stroke:#000;stroke-width:1px;}#svgGraph12817380037229 .rough-node . label,#svgGraph12817380037229 .node .label,#svgGraph12817380037229 .image-shape .label,#svgGraph12817380037229 .icon-shape . label{text-align:centre;}#svgGraph12817380037229 .node.clickable{cursor:pointer;}#svgGraph12817380037229 .root .anchor path{ fill:#333333!important;stroke-width:0;stroke:#333333;}#svgGraph12817380037229 .arrowheadPath{fill:#333333;} #svgGraph12817380037229 .edgePath .path{stroke:#333333;stroke-width:2.0px;}#svgGraph12817380037229 .flowchart-link{stroke :#333333;fill:none;}#svgGraph12817380037229 .edgeLabel{background-color:rgba(232,232,232, 0.8);text-align:centre;} #svgGraph12817380037229 .edgeLabel p{background-color:rgba(232,232,232, 0.8);}#svgGraph12817380037229 .edgeLabel rect{opacity. 0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#svgGraph12817380037229 .labelBkg{background-color:rgba( 232, 232, 232, 0.5);}#svgGraph12817380037229 .cluster rect{fill:#ffffde;stroke:#aaaa33;stroke-width:1px;} #svgGraph12817380037229 .cluster text{fill:#333;}#svgGraph12817380037229 .cluster span{color:#333;} #svgGraph12817380037229 div.mermaidTooltip{position:absolute;text-align:centre;max-width:200px;padding:2px;font-family:" trebuchet ms",verdana,arial,sans-serif;font-size:12px;background:hsl(80, 100%, 96.2745098039%);border:1px solid #aaaa33; border-radius:2px;pointer-events:none;z-index:100;}#svgGraph12817380037229 .flowchartTitleText{text-anchor:middle;font-size. 18px;fill:#333;}#svgGraph12817380037229 rect.text{fill:none;stroke-width:0;}#svgGraph12817380037229 .icon-shape, #svgGraph12817380037229 .image-shape{background-color:rgba(232,232,232, 0.8);text-align:centre;}#svgGraph12817380037229 .icon -shape p,#svgGraph12817380037229 .image-shape p{background-color:rgba(232,232,232, 0.8);padding:2px;}#svgGraph12817380037229 . icon-shape rect,#svgGraph12817380037229 .image-shape rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232, 232, 0.8);}#svgGraph12817380037229 :root{-mermaid-font-family: "trebuchet ms",verdana,arial,sans-serif;}
Manto transport

Feed on demand

coating line

3-tier buffer table

assembly line


pass (a bill or inspection etc)Photoelectric sensor + PLC control, realisation:

Automatic restocking of stackers
Buffer Capacity Enhancement 200%



​Tactic 3: The Access Revolution Reduces Collision Risk​



pre-conversion
after conversion
Benefits Enhancement




Two-way 2 metre mixed flow channel
Unidirectional 3.5 metre loop
Forklift collision ↓80%


pedestrian-vehicle interworking
Exclusive access to the AGV magnetic track
Logistics Efficiency↑35%



​Strategy 4: Digital Twin Preview Tray Traffic​

Simulations with FlexSim revealed that:

Packing line export stacking risk → addDrum diverter​
Waiting timeout at quality control station → Increase2 visual inspection machines​



​Strategy 5: Modular design reserve expansion interface​

Pre-embedded at the end of the conveyor lineQuick Connect Module::

30-minute access to extended segments when capacity is increased
Pallet Handling Capacity Increase 50%




I had an epiphany when the shop floor pallet inputs were optimised from 380 to 240 and logistics costs plummeted by 28%.Pallets are the blood vessels of the production system linking people, machines and materials - their number and position directly determine the strength of the pulse of the entire automation system.. Accurate calculation is the foundation, and system adaptation is the ultimate competitiveness.