Logistics & Supply Chain
Pack pallets, time reorders, and route trucks profitably.
Build the base
foundationPallet, Case & Each Arithmetic with Weight & Cube
Customer orders 3 pallets + 7 cases of SKU-7841 (24 ea/case, 40 cases/pallet, 2 lb/unit). Compute total eaches, pallet weight (cargo + 50 lb pallet), and whether the order rounds UP to the next full case when the customer asks for 5,000 eaches. Three-tier 'each → case → pallet' arithmetic is the entire WMS pick math.
foundationTrailer Cube Utilization & Density Pricing
53-ft dry van: 3,816 cu ft usable. You're loading 26 pallets at 48×40×60 in. Compute pallet cube, total cargo cube, % utilization. Then re-price as LTL: density = weight ÷ cube; freight class is set by lbs/cu ft.
Daily-job math
coreReorder Point, Safety Stock & Service Level
Sell 30 units/day, σ_demand = 8/day, supplier lead time 7 days. Compute base ROP, then add statistical safety stock for a 95% service level (z = 1.65) and 99% (z = 2.33). The safety stock is the cost of NOT stocking out.
coreFreight Cost-Per-Mile, Deadhead & Break-Even Rate
1,200-mi load pays $2,640 but requires 180 mi deadhead to the pickup. Truck does 6.5 mpg, diesel $4.10/gal, fixed cost $0.42/mi (driver, insurance, depreciation). Compute revenue/mi (loaded only vs all miles), fuel CPM, net margin, and break-even rate where margin → $0.
Master-class problems
masterInventory Turnover, DSI & Cash-to-Cash Cycle
COGS = $480k/yr, avg inventory = $60k. Compute turnover, days-sales-of-inventory (DSI), then layer in DSO (45 days A/R) and DPO (30 days A/P) to get the Cash Conversion Cycle — how many days your cash is trapped between supplier payment and customer collection.
masterEconomic Order Quantity, Reorder Cycle & Total Cost
Annual demand D = 12,000 widgets, setup cost S = $50/PO, holding cost H = $3/unit/yr. Compute EOQ, orders per year, cycle time in days, and total annual cost (ordering + holding) at EOQ. Then verify EOQ is optimal by re-pricing a non-EOQ order quantity.